Okay, I haven't read all of the replies, but I spray my entire "lawn", which is around 12 acres several times a year. By the beginning of summer I almost never have a dandelion in my yard. As opposed to your desires, I also hate clover and have a constant battle to rid my yard of clover.
I use Gordon's 2-4-D in general for weed control and Malathion for bug control. After the first spraying of 2-4-D, most of my dandelions will be dead along with a lot of other broad leaf plants. However, the clover only "looks" like it is going to die. It will curl and begin to turn a pale color. However, in about a week, the clover is back no problem. /forums/images/graemlins/mad.gif That prompts me to spray a 2nd time for it, and sometimes a 3rd. Wild onions are pretty well the same. /forums/images/graemlins/frown.gif
I called the Indiana - Purdue ag department and spoke with them about this issue. They explained to me that clover, most varities, have a waxy outer layer that protects the plant from a lot of herbicides. The first spraying turns out to be an even battle with most of the clover's protection. A 2nd dose will generally do them in. Also, I didn't know that clover is a type of "vine" plant. /forums/images/graemlins/confused.gif It does spread and the ag department does consider it a weed. However, as much as I dislike it, I would greatly prefer clover for bank control over kudzu. /forums/images/graemlins/blush.gif I have a tree line along a creek on the far west side of my property that the state of IN, in all their wisdom, planted kudzu in for erosion control back in the 40's or so. The best I can tell, no know herbicide will take it out. /forums/images/graemlins/mad.gif
For kudzu, I've tried straight concentrated roundup. That killed a huge circle of vegitation only to have the kudzu pop back up in the middle of the dead patch in a couple of weeks. I've soaked it with 2-4-D. I think that is a fertilizer for kudzu. /forums/images/graemlins/mad.gif I tried digging it out. Much to my dismay and surprise, I've found it will take a backhoe with a big reach to get it. The main root that will have to be killed drops as far as 12 feet into the ground!! /forums/images/graemlins/shocked.gif If you don't get that, it will come back. In 15 years, I've been unsuccessful in killing off the kudzu; I've only been able to control it. About every other year I have to go through the woods and cut the vine at the base of my trees or it will choke out all light to my trees and kill them.
Sorry, I got a bit off of dandelions, but I've been studying weed control for about a decade and a half now. I think I have most things figured out except that kudzu stuff. /forums/images/graemlins/crazy.gif