Weirdly enough, I could almost say the same about my reason for joining. To find out about this subject, but also to learn more about my weapon of choice, the good old D-Bag aka Mephedrone.
I do not do it as meticulously as some people mentioned above (although certain preparation is required due to excessive sweating), but I get certain surges where I do feel like I just want to go home and beat one out on drugs. For me it started when we were partying with my girlfriend quite a bit and realized that orgasms are insane while on stimulants once you are finally able to reach that point. So it started as "normal" sex or mutual masturbation between us few years ago, but has continued alone ever since. It's mainly spontaneous, but if I do know I have a day off coming up for one reason or another or my girlfriend will be away...the activity is quite clear.
I do not masturbate at all otherwise basically, I do enjoy sex with my girlfriend a lot and my life is more or less normal otherwise with a good job yadi yaa. But when I do go out and use drone, I usually leave in the early hours, which is sensible, but it means I will go home and beat one off. Or a few. I will also make sure that I have enough drugs to do so for several hours, which I think is me trying to feel better about my normally not-superhuman stamina (not 20 second man, but lets say 5-8 minute man). So being able to watch porn and crank one that lasts several hours is some sort of weird validation for myself that I can sometimes last longer than normal. I think the longest one is approximately 7 hours with rest breaks, re-dosing, trying to maintain erection because you took a tad too much or lost concentration, so we're talking about quite substantial times here. For the record, I have no psychological issues, that require medications or other apart from this, but clearly some form of inferiority, possibly because of a lot of porn
So it hasn't really killed sex for me, I am not very sexually active and have never been, but this does get me riled up. I know most people have coke wanks and so on, but I am yet to cross paths until now with people who actually on purpose do drugs almost solely for this purpose. While sober, no urges.
Advice on the matter....not so much as this particular habit has not in itself caused me any harm apart from a lot of towels and sheets that need to be washed due to sweat and an occasional soreness, but anything that involves these substances and becomes a habit, is quite concerning. I dont do great amounts at once (not even a gram usually), but the frequency of it is the killer. The power of the orgasm after a super-wank like this is so overwhelming and all-consuming that it is the thing that keeps me going back to it. Nothing beats a good fuck and making your girl cum, but I have noticed that these two are separated in my head and dont cross or interfere with each other. Luckily, even tho she is the one who it all started with.
So yes, we are out there it seems.