Adding traction to old sandals?

This might come in handy.

Shoe Goo is supposed to work in a case like that though I haven't personally done it

Soling rubber is sold by the sheet. Search online for cobbler supplies. You can get many different sorts of tread patterns.

However to glue the new rubber onto the bottom of your old sandals you'll have to remove all traces of existing tread. You've got to have a flat surface to glue the new rubber to. Maybe a belt sander would work. It will be handy to trim the edges of the rubber after you've glued it to the sandal, too. That way you can get a professional looking edge.

The gold standard glue to use is Barge cement. Master cement is another brand of it. It's the stuff cobblers use.

Sometimes leather shops have cobbler supplies, too.

You could try Sugru and see if that works.

http://Www.sugru.com

Mike