There’s so much misinformation around this topic, I really have no idea whether cocaine is actually a drug that can be used to benefit, Aleister Crowley certainly claimed so, or meth, or who knows.
On the crowley note: My time spent in occult circles tells me something similar. Some folks benefit, some folks don't and it has just as much to do with their particular slant on Thelema or other path as it does with their personality and reaction. Though I will say LSD, shrooms, DMT, pot, tobacco and alcohol seem to be the more common "helpers".
Now you could argue that it may also make someone else's life better, but we can't yet make any official research on the topic due to the legal framework against drugs.
On the misinformation clause - I can't say there's much misinformation on the dosages and expected effects on the hard reduction websites. They do their job well.
The kind of stuff that deserves to be regulated, is the stuff that has known health issues (including strong physical addiction, as e.g. opiates do).
94. DE VIRTUTE EXPERIMENTIAE IN HOC ARTE. (On the Virtue of Experience in this Art) Not Sleep, not Rest, not Contentment are of the Will of the Hero, but these Things he hateth, and consenteth to enjoy them only with Same of his weak Nature. But he will analyse himself without Pity, and he will do all Things soever that may free and fortify his Mind and Will. Know that the Technick of the Right Use of this Magick with Poisons is subtle; and since the Nature of every Man differeth from that of his Fellow, there entereth Idiosyncrasy, and thine Experience shall be thy Master in this Art. Heed also this Word following: The Right Use of these Agents is to gain a Knowledge preliminary of thine own Powers, and of High States, so that thou goest not altogether blindly and without Aim in thy Quest, ignorant of the Ways of thine own inner Being. Also, thou must work always for a definite End, never for Pleasure or for Relaxation, except thy wilt, as a good Knight is sworn to do. And thou being Hero and Magician art in Peril of abusing the fiery Agents only, not those of Earth, Air or Water; because these do really work with thee in Purity, making thee wholly what thou wouldst be, an Engine indefatigable, a Mind clear, calm, and concentrated, and a Heart fierce aglow.