Thanks for the advice, i'll try that trap after I move a colony of Frogspawn(I hope it doesn't scare the shrimp into changing it's burrow). I had thought the old "pop bottle crab trap" trick wouldn't work on a timid pistol, covering it is genius, I am pleasantly surprised.
JoeMomma, I just want to be able to dose interceptor and not kill the poor little guy. The shrimp and it's goby buddy are highly esteemed and i'll just move them to a different tank. I highly recommend them, they are interesting and have their own endearing character. Just make sure your rock is secure and firmly planted.