Now, at first I thought it was a fluke, but after waiting a few hours, and the twitching returning, niacin once again obliterates the twitches

It also seems that it reduces twitches somewhat even after it wears off, but that I can't say for sure.
I am having "success" with a dose that just barely flushes - and you develop tolerance and can increase the dose accordingly.
at first, about 70 mg was enough to make me flush badly. Now, i'm up to 250 mg doses, every few hours. - I'm on week 3.
The best way for me is just to empty a 500 mg capsule in a large bottle of water - "niacin water" - it doesn't dissolve but you can shake it. This lets you get a more stable dosage. Another way is to just sprinkle some of the crystals on a clean surface and lick em

Other than the flushing, which is minor for me after taking it a while, i always get a "calm" feeling - like not tired like i'd get with gaba, and not difficult to breath like with alot of sedatives, but just like a clear feeling.
The effect is only temporary for me , but i'm wondering how it works. Niacin is a vasodilator, so maybe some capillaries are clogged with some kind of pathogen, or maybe it has something to do with histamine's effect on nerves ??
Niacin supposedly disposes toxins from the brain into the general bloodstream - i don't know of the accuracy of this, BUT it is for sure good for keeping cholesterol in check & reducing risk of stroke, etc.
Anyway, it would be interesting to hear if anyone has tried this.