Hey there,
I have some figures with loose ball joints but never resorted to the super glue trick. I just see that as a permanent foreign material therefore technically modifying the toy. Anyway, I decided to go and research the topic again since its been probably over a year since I've last done so and came upon a fantastic solution.
Adding a little bit of paper to the cup adds mass and makes the joint tighter. It doesn't work for everything but I've used it about 10 times successfully. My Gashapon Bumblebee Sword has odd cups with tabs in it that prohibits the ball from going into the cup all of the way. I even opened my Generations Kup and added some paper into his head because it was super loose. Like someone gave him thorazine loose.
Anyway its not permanent so it meets my needs. It will wear out over time but its just paper and it doesn't take much. A sheet of loose leaf may last you a few years. I found it a handy tip and wanted to share.
Thanks for reading, I hope it's of use one day.
