I use to run tubes a few years ago. I had one tube that had been in a tire so long it bonded to the tire. It was a pain in the azz to cut it all out. Still never got it all out and I'm sure the tire was out of balance , but that's not a problem for my tires. I do use a little black silicone around the bead to keep from leaking, but it's a pain to clean the bead when you put another tire on.
If it's a rim problem I've also had to use a little green slime. Wipe it all over the rim don't pour it in through the valve stem it takes way to much to do it that way.