well....I just think about it from time to time "Gee, what if someone put something in here in place of the real stuff to make a quick buck and if messes me up. (And they add it in there by mistake thinking that it would be ok and I run into problems.....like they have to remove a chunk out of my ass!)
There is no way in hell that Isopropanol can be good for your body, in fact, I think that it could have some serious effects! I know that methanol can cause blindness if it is ingested (wood grain alcohol)
I would at least keep trying to get in touch with the guy. If he takes and and something happens, he is going to come looking for you.
Not trying to beat a dead horse....just trying to give you a heads up. We all make mistakes.....just don't want anyone to get hurt, including you.
later