I have done the niacin/conventional sauna combo but never tried the exercise part as Mercola suggests. Niacin flush alone at 180 degrees is heart warming!
I've also used niacin to push oral Iodine tincture through niacin dilated capillaries. It's like Iodine on roller skates. Niacin really opens up the plumbing and just getting strong blood flow to stagnant areas must be somewhat detoxing as Mercola suggests.