The squeakers I kept for use when training Charlie. Especially when he is barking. SOmetimes it works most times not.
I ended up with really tough balls from Chuck-it. Charlie finally tore one ball that I bought when I moved here 4 years ago. So they are a good buy.
When I had BOR I gave up on toys and instead bought towels at Goodwill, if I didn't have old ones. Not everyone used them and they were kept for in-house use only. They were medium and tea towel size. It worked. For they would drag them around and play tug with them. No great loss.
I hope you can find something they will enjoy but can't tear apart. Good luck!
Love All Life, Thank You For Posting! :)