I've heard of using vinegar before but haven't seen a product sort of made for it like the above. The vegetable oil idea is interesting, but I see side effects. At least it wouldn't contaminate like motor or hydro oil. I'll have to check on 'Polymetric sand'.
This is all related to my other thread about a shed roof/overhang and trying to get water away from the house. In the sketch below, the house is on the left, breezeway between house and garage on top, and garage on the right set at an angle to the house. The grey square is an old concrete cistern. Ground is nearly flat/level around and behind that, which leads to rainwater collecting in the blue oval area. Once I get the shed roof built, no more rain will fall on that area and the plan is to grade the 'courtyard' off towards the green line to keep rain that falls on the remaining uncovered area to drain away.
The cistern leaks a bit and at least some rainwater collects inside it, even though it's covered. That should stop once I get the water/drainage resolved. Then I can uncover it and set a grate over it for safety that will let it air out and dry. There's probably a couple of feet of water in it that will have to be pumped out. Until that happens, I'll have to watch for algae and mildew growth under the new shed roof.
Once all that is done, and the area can dry out, I can set pavers as I have funds available. But in the mean time, I don't want any plant growth anywhere in that area that can draw and emit moisture. Lack of Sun will help, but there will be enough from the open side to allow some. The end goal for the area under the new roof is to be as dry and barren as possible, desertified, moonscaped. Dry enough for the ground surface to crack and become dusty.
This all goes back to the Termite issue. I've got to get any and all water away from the house and this is a problem area that stays wet. It's been too wet to even treat with the pesticides mentioned. They would just get diluted and become useless.
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