OK, I said I'd post so here they are.
The first pic was my attempt with a baby bottle. The problem with that is the worm was able to easily enter the bottle and eat the bait without ever extending that far from the rock.
This is what worked:
A simple piece of tube with a cap on each end. It's hard to see but there's a piece of fishing string and a small loop tied to the string for extracting the tube from the tank.
This shows the holes drilled in each end. 1/4" hole. What you don't see in the tubing is the fishing weight and the piece of shrimp used for bait.
You can see the fishing weight in this pic. I dumped the contents of the tube into this drink bottle which included the worm. The tube you saw in the sink is about 18" long. The worm was still in the rock and extended from one end of the tube to the other to get the bait.
So there you have it. You should be able to make something close to that and catch the worm. I put mine in a bottle of tequila. Not really, I took it to the aquarium store for show and tell. Good Luck