Bonnet Worms?

I do most of my fishing in north central Florida, mainly lakes Orange, Lochloosa, and Newnan's. Back in the day and I'm talking 40-50 years ago, I heard several old guys talk about using bonnet worms for bait. They were supposedly deadly, even better than grass shrimp for both bream and crappie. Supposedly you got them by pulling up lily pad stems and slicing the open to get to the worms inside. I've tried this numerous times and there ain't no worms to be found. Anybody been able to figure out how this is done?
Thanks

:popcorn No clue but interested in it.