Ok im going to be doing some dxm with my friend and we bought 2 bottles of 20 robotussin with only dxm in it, the problem is (this might sound dumb) but it says dextromethorphan or whatever then after it it says HBr......and on the front of the bottle it says non narcotic, will these work? if so how many should we take, we both weigh around 145. also i was wondering about how long they will take to kick in. thanks