A secret source for a lot of strong chemicals is the pool aisle at hardware stores. They have sneaky names like “pH reducer”, but that shit is hydrochloric acid. There’s other good ones too.
Another good source is salon supply stores. You can buy full strength hydrogen peroxide and other things. The stuff you get at the drug store is very diluted.
Laboratory supply stores will still sell alarming shit to you also. It’s a bit surprising how many crazy things they will sell anyone no-questions-asked. The safety mechanism seems to be that most people don’t know what some of that really dangerous stuff is or what it’s called. It’s also generally very expensive and in small quantities so I guess that keeps most people from doing anything too stupid.
