I've never tried it, so maybe someone else has a different opinion, but I would advice against it. My experience has shown hot glued items to not hold up so well in such conditions. I'm not sure what is in those glue sticks and that is an important thing to know. Most people would use aquarium sealer that you can get at your lfs
or a walmart. It works well but for the tiny tube you get, it's a lot of money in my opinion... You can also use silicone from the hardware store... You just have to make sure that it is clear, %100 silicone with nothing else added. If you read the tube I believe it says that it's not for things that are going to stay submerged but believe me, from experience, it will work... and I can say for sure it will work better than hot glue. The stuff at the hardware store is cheaper than the aquarium sealer... It's affordable... what does everyone else think?