Hi Ken,
Did you try to use bass drop shot for cat fishing? I have added the slip bobber + slip shot, and I am very satisfied with the results. I use this rig during boat anchoring and drifting.
Anchoring:
In the shallow water, it works as the regular slip bobber rig with the sinker (1/4-1 oz) on the bottom. In the deep water, I use 1 oz sinker, and the submerged bobber keeps the leader in the vertical position.
Drifting:
If I use 1 oz sinker, the baits move along the bottom. If I use ¼ oz sinker, I can fish at any depth, changing the stopper position.
Replacing the sinkers is very easy, using the fishing snap.