An important point to remember is that the chemical is only meant to turn the powder into liquid. Once it's a liquid what you have is a highly concentrated solution that needs to be diluted with distilled (preferably) water to be safe to use on plants. To figure out much water to add you need to know what PPM (parts per million) solution you will be using. For this please take a look at the PPM calculator.
If you are using some very strong solvent like lye or some kind of acid there is a normal concern about damaging the plants. Actually, you will be using so little solvent that when the solution is diluted the solvent will have no strength at all. The idea, of course, is to use only a much solvent as you need. Start by putting the powder product in a small glass container with a small amount of water. Then add small amounts of solvent and try mixing the solution. If it dissolves then great, otherwise add a little bit more solvent and mix some more.
Alcohol is not a strong solvent.
If you need more information than what is provided please send us an email!