If I'm not mistaken, crawfish CRAWL forward (else those eyes aren't of much use). The do swim backward and when in a defensive position, kinda stick their pinchers up at about a 30-45 degree angle. And swimming may not be the right word. They "dart" backward usually a few inches at a time, though can do multiple darts in succession (swimming). So, while you're trying to "be the bait", keep that in mind.
Also, as demo'd at BPS, a bass will literally inhale the crawfish and blow it right back out. Reason? To break off the pinchers. So, if you miss a bass, just let her settle right back down, she ain't finished yet.