delsym would work but its hard to find and alot worse for you than other ones....

but you are right that the ONLY active ingredient should be dextromethorphan. One of the reasons that you shouldnt use it very much is because of those extra nonactive ingredients like the pill shell and the goop and stuff which isnt good for you at high doses. But dont worry about them.

I reccomend the robituss 8 hour coughgels because they are easy to down and if u take the whole bottle u trip balls from anywhere to around 7-11 hours. just remember dont do it more than once or twice a month at most... most p[eople do it 3 times a year or less.