yeah, id say keep em... they are great for a clean up crew...
now having said that... since ive never had a problem of not having enough of them... i seem to get bristles stuck in my fingers everytime i pick up a rock from my tank... then the worms seem to accidently drop in my toilet! oops!
i just cleaned one of my return pumps and i found a bunch of em living in the pump housing!
when my buddies would come over they would always look around my tank and wait for the big suckers to start crawling around!
when i catch big ones i usually toss them... if there is a demand, i could sell them to you guys!! hahahha seriously though if you guys want them, i can let you know when i have caught a few big ones and you can come pick them up!