Tom, I used to have a small tool that I bought that was made just for this and ran off of batteries kind of like a small soldering iron. I used it all of the time. One of the biggest bass I ever caught in a tournament was caught on a floating worm that I had repaired 3 times back in the day when the Fliptail Lizards were not being made. I still have a plastic bag with about 100 CrawTubes I need to fix now that I am doing a little more fishing these days. Added a few more after fishing Cedar Creek yesterday. I will look and see if I can find it but it was pretty easy to plug up holes and repair tears. It also gave a kind of funky neat look to some colors of baits. If I find it I will let you know and you are welcome to it.
Oatey 31013 PVC cement. It has a tendency to gel after several uses, but if you cut the dauber off and pour small amounts out of the can rather than dipping a brush repeatedly into the can when applying it, this is minimized.