I haven't done it in a while but I was just reading a report of someone who did, and I remembered the hilarity...
First the fuck of all, this drug is not normally fun, the general population considers it one of the worst drugs in existence(for recreational uses that is, it's actually quite an effective antihistamine).
All the experiences I've had with it have all included very clear audio hallucinations, scratchy and shadowy oev's, accompanied by a heavy body load, and a general feeling of discomfort. However, this drug can have it's moments of hilarity. I remember walking, about to round a corner being in anticipation of something bad being around it and hearing horror movie themes building in intensity as I got closer to the corner. When I would turn the corner nothing would ever be there, and I would laugh hysterically every time. Seriously, hard laughter, I mean the hardest I've ever laughed. If you can get yourself laughing, it can be slightly enjoyable. i remember being in such a ridiculous amount of misery that it became funny and I laughed for nearly half an hour, until I forgot what I was laughing at. One thing that was truly annoying was the lack of short term memory. Ideas won't stay in your head for too long and conversation will be difficult because you won't remember what the fuck you were going to say to whoever you were talking to. Audio is often what brings the laughter. I once heard a woman right outside the door yelling for help, but to my shock she was not there. I would constantly hear news report sounds, siren type noises, and terrifying hissing/growling noises.
There were oev's, but most were 2 dimensional, and grainy. I had this really annoying jackolantern guy that would appear on the wall and hiss at me. Even though I knew it wasn't real, I would still get terrified from looking at it for too long. I only had one hallucination where I had trouble telling its falseness. I was laying on my couch and a reptilian looking man/thing entered the room and stood in front of me. He was breathing heavily and drooling. It was so vivid that I could see the moistness of his skin on his 3 dimensional body. I was incredibly terrified. It was hard for me to believe that something that vivid wasn't real. I had to force a reality check.
Like I said, it's normally not fun, I've done it nearly 10 times from very light to very heavy doses. It doesn't change in character as you increase the dose, it just gets lamer. So take this drug seriously and consider yourself warned.