What does disarming mean here?
I wound read it as “the drug has less effect” - so in that case you can better abuse these drugs if you are worse at “disarming” them I guess
I would have thought the main armament that nicotine has is its addictiveness
perhaps "making less harmful to the body"? this could potentially be accomplished separately from making them less effective
"Hard headed", "not a cheap date", "not a lightweight"? Hard to say if increased tolerance is good or bad (especially if we're uncertain about how addictiveness/susceptibility to addictive behavior it passed)