this discussion comes up and around here occasionally.
i personally know fuck all and would look to deep to come in here, but here goes nothing:
it makes sense that a pill broken up, chewed or dissolved in the mouth would hit harder and quicker than one swallowed. Follows that it would also metabolise quicker leaving a shorter roll.
and the point of plugging up the jacksie is to get it into the intestine where it can be absorbed quicker, and bypassing the stomach acids which may eat at the pill and break it down. as a sidline, some people swear that if they are having trouble with a "teasing roll" (ie not quite coming on), a big crap will fix the problem, ie move it down into the intestine. FOod for thought (no pun intended)
cheers
pinger