i got a small green (maybe an inch long) hitchicker pistol shrimp in some zoos. He lives in the very little hole. Since he doesnt have a goby to guide him, he just hangs out way deep in there. There must be tons of tunnels in there. I shine a flashlight a few inches back and i sometimes see his eyes. i only know it is a pistol because like 3 times he has come up to the mouth of the hole when i happened to shine my flashlight there. So i was able to see his claw. But i too see his little eyes reflecting light back at me.
mudplayer; depending one the size of the whole or what is in there, try putting a turkey baster up to it and sucking it out. Lick stick it in. The whole would have to be very round though. But if its something like a large featherduster hole it would be. I have a whole that is almost perfectly round. it looks like the inside of a riffle.