all the cleaning you did should have them stuck together forever... i think it's the glue that went bad... they may look fine and works well to stick your fingers together... but they don't fuse the plastics and rubber together like when they are new...
try loctite 406... they'll stick them together till the tires tear and shredd and will still not give way....
ca tends to get thicker when they are going bad... once that happens, it's time to throw them away.... so, bottom line is, buy the smallest amount that is available, unless you run a tire glueing business...