I in no way recommend or commend using Dimenhydrinate in a manner inconsistent with its labelling. The same with Methylphenidate.
I experimented with ritalin for a long time and my curiosity lead to addiction or habituation. Starting with doses of 20mg snorted and building up to a daily 80mg of insufflated bliss. I did not realise I was addicted until long after it had happened.
At this point I seeked a substance to calm my cravings. I tried low doses of DXM (15mg - 60mg), other stimulants like Caffeine and Ephedrine, Codeine, Chlorpheniramine Maleate, Cannabis and other substances. Eventually I found dimenhydrinate and diphenhydramine.
a dose of 50mg dimenhydrinate equalled about 30mg Diphenhydramine. Dimenhydrinate quelled the urge for ritalin substantially and also surpressed my smoking and need to smoke. Along with this I get the best night's sleep for over a year.
I relapse now and again but Dimenhydrinate seems to stop ritalin from giving me a high, cutting out the pleasure connected with abusing ritalin definately helps the situation.