Captain Hook uses the clumping litter.
We got a couple of big bathroom "rugs" at a thrift shop that sit under and in front of his litter box and get shaken out each day. They seem to pick up 90% of the stay litter.
He has his claws and when we are at anchor and leave the boat, we hang a big old beach towel (thift shop again) over the ladder. He has never jumped off the boat, but, just in case.
Irwin Citation 34