When I bought my place it came with a dozen Greyhound bus sized burn piles all laced with both dead and live poison oak. Most of the land was covered in poison oak. There are laws on the books around here that forbid burning poison oak. But here, there's really no choice, so one by one, I torched the old piles, waiting for a damp day in the winter with little or no wind. Once the fires were lit, I stayed away and out of the smoke. Never had a problem.
Two summers ago a neighbor brought his dozer over and started knocking down scrub oak, manzanita, and huge poison oak vines. That all went into new burn piles, almost forty of them, all bus size. It took all summer, working a few hours most days. That winter we burned, burned and burned some more. Still no problems with smoke because we stayed out of it.
Prior to the dozing, I was trying to pull the plants with the 4-in-1 on the FEL, and lopping shears where I couldn't get the tractor. Needless to say I got PO a couple of times, but eventually developed a routine that has kept me free of it. I always wear gloves, long sleeve shirts, and long pants when working around PO. Also keep the collar tight on my neck, because I've had dust fall down the shirt front and start a rash at my belt line. My belt is nylon with a plastic buckle, and it goes into the washer with the rest of the stuff when I'm done. If I get hit by a plant and notice it, I'll stop whatever I'm doing and rinse off with cold water, which seems to take care of it. I also love to mountain bike, and sometimes you can't avoid PO on narrow trails. In those cases I use water from my pack or bottle to rinse the effected areas, or take a dunk in a stream if there's one nearby. When I get back to the car, again I strip off and put the contaminated clothing in a plastic bag, then it's directly into the washer when it gets home. That keeps the oil from contaminating the clothes hamper or other clothing, or having someone else unwittingly handle the clothes next time they do laundry.
At the end of the work session, I rinse my gloves off at a hose bib, just leaving them on and washing them like I would my hands. They're elk skin, so I leave them in a shady spot to dry and they're usually good to go again in the morning. I also rinse off any tools I've been using, even the tractor, with cold water out of the garden hose. Sometimes I'll use a brush, but mostly just cold water seems to work just fine. Things dry quickly in the sun out here, and I usually don't bother with WD40 or the like. Finally I'll rinse my boots off, and sometimes use a scrub brush on them, again just using cold water. I always finish by rinsing the hose and nozzle off, then my hands one last time. During all of this I imagine that everything I used or worn out in the field is contaminated with PO. I used to work in nuclear power plants, and that was the routine used there to prevent the spread of contamination, so I figure the same will work for PO oil. So if I turn the hose water on with dirty gloves, the faucet handle gets rinsed off and I only touch it with clean hands after that. Same with tools: handle them with dirty gloves when they're dirty, wash the gloves, then the tools, and handle them only with clean hands or gloves after that.
Once my hands are clean I'll go into the laundry room and strip off everything into the washer, taking care not to touch the outside of my clothing with my clean hands. I try to touch the cloth only on the inside, and will pull my hand up into the end of my shirt sleeve to make a little glove I can use to work buttons, belts, and snaps and pull off stubborn clothes. I always keep thinking "dirty to dirty, clean to clean". When I'm standing there in my birthday suit in front of the washer, I run it in a heavy duty mode with regular laundry detergent. Sometimes I'll throw other stuff in there to complete a load, and haven't had any problems yet. But I'm very careful not to let any of the clothing touch the outside parts of the washer, only the inside that sees wash water.
With the wash started, I'll jump into the shower, using cool to warm water and Nutragena soap, mostly because I like the smell, but it seems to do the trick. When I know I've been dosed by a plant, I'll hit those areas with one of those natural tufa type scrubbers with straight soap on it, rinsing with plenty of water and maybe repeating the soap. Avoiding a rash is as easy (or difficult, as the case may be) as keeping the oil off your skin, or failing that, getting it off as quickly as possible.
I also use the same soap on places where I've got a rash, only using the hottest water I can stand. I figure that the hot water will open up the pores in my skin and let the soap get to the oil better. That's just the opposite of what's needed when the oil is freshly applied to the skin, where cold water will keep the pores closed and rinse the oil off before it has a chance to penetrate the skin. The Nutragena treatment dries out the PO in a few days and provides some temporary relief from the itching. That first year I got PO pretty badly a couple of times and my doctor wrote a prescription for Triamcinolone 0.1% cream. It's white and a little goes a long way. I've learned to rub it in until it disappears, otherwise it doesn't do much. Used that way, though, it takes care of the itch and the bumps/blisters go away in just a few days.
That same doctor told me that as I am get more exposure to PO my symptoms will worsen, and that there's no such thing as being able to build up an immunity through repeated exposure. I have a neighbor that swears he eats leaves of the stuff regularly to build up his immunity, but he also says his son is naturally immune and I suspect he is as well. The doc also said that the oil will spread inside the body, and I've seen it myself in my own body. There are injections that will provide an immunity, but my allergist refuses to give them as the antigen frequently leaks from the injection site. That causes a rash on the patient, and frequently on the nurse as well. I wear PJs to bed when I have a rash, a fresh pair each night. That keeps the oil from spreading from the rash sites.
The dozer was the very best remedy for clearing PO off the land, but two years later I'm still getting new sprouts and finding places we missed. Every spring I fill the backpack sprayer with a mix of generic Roundup (I get mine at Tractor Supply) and generic BrushBGone, mixing each with the indicated amount of water to fill the tank. It's a pricy blend, but the Roundup will get in through the leaves, while the BrushBGone goes in through the trunks and stems. Sometimes I'll throw in a spritz of Dawn dish washing detergent, but I've leaned to save that for after the tank is full to avoid creating a foaming mess. Then I just walk around the property spot spraying any plants I run across, and don't worry too much about keeping it off mature trees. I've noticed at least three distinct varieties of the plants around here, but they all respond to the treatment. Even the thicker vines are killed by the brew (the ones here aren't the monsters you guys deal with, but they're over an inch and too big to pull down), but it might take two or three doses. Then I'll hack off the root and pull the plant out of the tree with the 4-in-1 on the FEL, throwing the stuff onto a burn pile for winter disposal.
I always end up missing a few plants, and some sprouts later, so I'll do another hike in a month or so to pick up any stragglers. I've tried dye in the water to help me keep track of where I've sprayed, but so far I haven't found one that gives a strong enough color and doesn't cost a fortune. When I'm done I go through the same decontamination routine outlined above, because no matter how careful I am when I'm walking around I always seem to end up standing on or next to a plant I didn't notice until it was too late.
They say God works in mysterious ways, and I gotta say that between PO and mosquitoes, there's a lot of truth in that. I think I'm finally getting the upper hand on the battle around here, but I don't think I'll ever be able to drop my guard and miss my monthly spray patrols.