As far as i'm concerned it's seriously dodgy probably christian moral propaganda.
If someone is masturbating so frequently it affects their life negatively because they don't have time to do more important things, or are suffering from excess chaffing, then sure, cut down. If you have an obession with porn that means no real women will ever live up to your standards in terms of appearance or easy availability at the click of a mouse button then maybe cut back on that and try and reconnect with real people and it will do you some good.
I just don't see that not masturbating for 3 months or whatever is actually going to be any real benefit to anyone. The body clearly isn't designed to repress basic desires like eating, sleeping, sex or whatever and there is a
good deal of medical evidence to suggest that occasional masturbation lowers the risk of things like prostate cancer and is basically healthy.
There's even evidence to suggest that stress is such a health risk that bad habits like smoking and drinking (especially light smoking and drinking) can be healthier on balance if they reduce your stress than the health risks of the stress itself. Given that masturbation is probably one of the easiest, quickest and (compared to smoking and drinking) healthiest things that you can do to lower stress, it must be good for you.
The kinds of people that go for stuff like this are usually either moralising christians who think sex outside marraige is somehow wrong or else anoying new agey types who go for reiki and transcendental meditation and only eat raw foods that want to be eaten and crap like that.