My buddy does it when hes power lifting and trying to max out.
He keeps it to once a week, twice max..but he only does it every other week or less. I feel doing it
too often would make you reliant on it in some way. I have yet to try it, but he says its like getting
a fast, hardcore boost. Like someone shot you up with adrenaline and it gives you a big head rush
but still lets you focus in.
He ALWAYS lifts heavier when he does it, the shit works and I have seen many people utilize this method.
Antoine Vaillant has quite a few videos of him going for 1-3 rep lifts on heavy compound exercises where
he takes a whiff or two before hes about to go. You look like a tweaker doing it though