Yes… After being reminded of that, I went looking in ACKS for the exact details of what happens when you mix potions and was rather disappointed by the lack of a table. (…which is not something you hear often when talking about ACKS!)
I don’t suppose anyone might have a link to an online Potion Miscibility Table handy? (Doesn’t need to be an official TSR table, just something appropriate for giving players the idea that “you really shouldn’t do that unless you’re truly desperate”.)