There's no doubt that the flick is an uncommonly clever spoof like those of the Wayne's Word and Blues Brothers comedies, and there's no doubt that writer/director Jorma Taccone (along with writers Will Forte & John Solomon) knew exactly how to hit their mark in spoof-making the skit about a goofus explosives expert who bumbles his way from one self created disaster to another.
According to the writers, none ever supposed the script would be accepted for filming, so they pulled no punches in creating it, playing it as politically incorrect as possible while pushing the raunch as far their imaginations could allow. One situation that ignored explanation (as most of them did) involved our erstwhile hero appearing with a stalk of celery stuck firmly in his butt - later to be chewed by him with the aside, "I cleaned it first." That brought a mix of astonished gasps & broad laughs. Naming their adversary Dr. Cunth (the "h" silent, of course) was a repeated source of low guffaws.
The gags come thick & fast, but pretty much hit & miss, with some repeated far too often to raise a laugh. Will Forte as MacGruder is in his element, handling it with more tongue-in-cheek than Joe E Brown's mouth might hold; he'll definitely be back for more of the same.