If you aren't using them in near freezing temperatures then Gorilla tape will work (it'll stop sticking as the temperature drops).
If you want something a little more refined than duct tape, there is product out there called "Freesole" by Gear Aid.
I've used it to reattach soles on work boots and hiking boots. It's pretty awesome, but you have to follow the directions and it needs to cure for a long time; especially for heavy application (it could take a week or more).
Since the crack is at the stress point on the clog as you take them on and off, the Freesole may not even hold up. In which case the lame-sounding Gorilla tape fix might be the better one.