Never cooked em or ate em, but as a kid we had a friend who's dad did. We would tie washers on a string and go down to the river where the shore was rip rapped and hang the washer in the crevasses of the rocks and catch a gallon pail full and give to him.
I caught quite a few in the bwca one time and steamed them up in my percolator. They were not that large, and they didn't taste great but I didn't season them or anything. It was a great one-time experience.
Trap? Pshhh....just go find a rocky coffee dam at night and scoop em up in a dip net. They start gathering n climbing up the dams and wet rocks at sunset. I can usually fill half a five gallon bucket in an hour or two.
I have caught them at Northgate and eaten them, boil them up with some crab boil, taters, corn etc. but they are better when they get cleaned out for a few days.