For the comedic value, have you tried He Who Fight With Monsters? It’s my most reread series by far, and is what I always give people after Carl.
Cradle is the other big one. The first half of book one is a bit of a hump for me, similar to reading Kal’s perspective in Way of Kings, but it picks up fast. The audiobook is magical; just about anything read by Travis Baldree is worth the time.
Rabbits I’m not sure. Cats naturally want to bury their leavings, so they actually train themselves just fine. Show them where it is, keep it clean, and 99% of the time that’s that.