I seldom fish in fly fishing only waters, and those few times are just for trout.
I do know that a small plastic worm on a hook is deadly when presented with a fly rod for bass fishing, and fortunitly bass waters are more egalitarian and you can use pretty much whatever you want to fish with. I think it's because bass are much harder to catch than trout anyway, and don't need the protection such restrictions provide.
I've even caught some really nice bass using a live nightcrawler with my fly rod, but it takes a quite a bit of casting skill to keep it from leaving the hook, and few fly casters can manage it. The very first time I fly fished for trout, many, many years ago, we were using what they called 'red worms' back then. Just a small hook with a live worm. Worked really well. So does a single salmon egg on a hook. And the new Berkeley 'Trout Worms' are awesome trout baits. Not something for fly/lure only areas, though.
In any event, the only trout I've caught on the diving baits I use have been ones caught accidentally while fishing for bass. These things are time consuming to tie and I can catch pretty much all the trout I want on simpler flies. I save the more creative stuff for the bass.
Buddy