Salicylic Acid is a major ingredient in many OTC Acne products, and also in OTC wart remover products. I’m sure you could find a product that would be easier to purify then making Salicylic Acid from Aspirin.
Good point about wart remover products. I think some of those are just salycilic acid dissolved in t-butanol. I don’t know how harmful t-butanol is to plants, but it is easy to get rid of.
To get rid of it, I would simply pour it on a flat surface to let most of the t-butanol evaporate. This might take a few days. I don’t know how much crude salicylic acid you will get out of this, but to wash the rest of the t-butanol away, I would just add it to water. Salicylic acid has a solubility of 2g/liter, so it probably wont go into solution unless you use a lot of water. Then you can filter it. A coffee filter should work just fine.
This will still have a small amount of t-butanol in it, but I don’t think it will be too bad. If you wanted it super clean, you could recrystallize it, but that isn’t something a non-chemist will be very successful at.
If I had to guess, one of those bottles might have about 1 g of salicylic acid, but I can’t seem to find the actual amount.
Thanks. I am going to try and age some aspirin first, because, as I have noted the hobbyists information sources are riddled with “aspirin” suggestions.