I used Gorilla Glue to repair my wading boots. It worked just fine on the soles.

I couldn't get a c-clamp to work to hold pressure on them so I put some newspaper down on the floor and put a table leg into the boot, then I put some weight on that end of the table. The glue expanded (like foam), when it dried I just trimmed the excess off with a mat knife. And yes, you are supposed to wet the object prior to using the glue.

People have told me that Goop works best. My local fly shop owner told me to use Barge Cement. When I couldn't find either of those things locally I tried the Gorilla Glue and it worked.