Haha oh man.. I used to dex trip ALL the time...
http://dextroverse.org/
check it out if you haven't already alot of good info there if you are curious.
Just quick info not sure if its been posted in here yet or not but..
You need to look at the active ingredients and make sure it is ONLY DXM!!!!!!!!
You could overdose on the other shit and DIE or get super sick, happened to a buddy of mine who didn't check before he downed like 2 bottles of gel caps.
Initially I found it easiest to do the gel caps 3-4 pills at a time, but after a while It got to the point where even thinking about swallowing gel caps makes me sick.
The best way to down it is to just pour out a bottle of liquid tussin in a wide mouthed glass and just pound it like some liquor.
Also, dxm trips vary by weight/dosage.
I weigh about 130 and I take 600MG for a pretty intense trip.
There is a calculator on dextroverse, I would highly suggest using it
I remember the time I did 750MG and was tripping so hard I got stuck in a time loop thinking the same thoughts about why the same shit kept happening over and over again as this oscillating fan pulsated back and forth, I had temporary amnesia and forgot who I was and where I was, but shit was just fucked up and kept repeating and I couldnt find the strength to pull myself up from the bean bag chair I was in... it was so crazy haha.
The 'afterglow' is the only drawback, its pretty much an 18 hour drug, you can sleep on it once the peak is done but you are hazey the next morning.