I must say that marijuana can, in some cases be a good alternative to other medications. I say this because marijuana is a natural substance that comes from the earth while other medications are manufactured. Manufactured drugs or medications can contain chemicals that cause other issues within the body. If marijuana is a good substitute and the patient is willing to partake in the treatment, then it should be permitted.
I don't think that smoking anything will actually cure anything. You have wild claims, and perhaps some that read information of it's healing properties, but they may very well be people who want an excuse to smoke. Some information claims that marijuana can cure, or at least treat hundreds of medical problems, but that's a rather steep number for a single herb that grows in the ground. It may be denial, or an excuse to indulge in it, but I hardly think that these claims are realistic. I would trust proven alternatives over fantasy "claims".