I cheap out... I have a yogurt container with a bunch of holes drilled in it so the water inside and the water in the tank are contiguous. (yes, it's a word, it means all connected). I hang the yogurt container in the tank, not touching the bottom, by punching a chopstick through the sides of the yogurt container and bridging the chopstick across the top of the tank. Not elegant, not fancy, but it works. Works really well with a bolt carrier group, trigger sets from a GSP, brass, parts from the browning trombone bolt... basically anything greasy or caked with carbon...