Good question! *That* is the single most irritating move in the game. It deals an asshole of damage, hits most of the screen, is very hard to block, and is considered a regular special move, so the guy who does it (a balding NRA gun-nut named Mongo) can, and will, spam the dildo-poop-bombs like crazy.
I only played this game once while it was still in the arcades (it's available for MAME, if you're interested) but I lost three whole dollars to those damn dildo bombs. Seems bikini ninjas are no match for napalm.