I have "hallucinated" on hash before (felt like a comet going through space, and i could "see" stars and planets pass me ! I was sitting down lol) . But the hallucination wasn't hardcore, I could still see stuff around me but I was plastered to the seat though lol.

On weed, after drinking cannamilk/ weed milk / bhang whatever you want to call it, I could swear many times over that the TV was on when it really wasn't, it sounded like a tv show was airing lol . That's about it .