not a normal scratching issue

Billy and Blossom both use their scratching posts and the old armchair that is theirs to scratch and sleep on--I've never had problems with them scratching the wrong furniture.

But Billy has a WEIRD habit. When he visits the litterbox, he doesn't cover his business but will turn around, head sticking out of the covered opening and scratch. First he wipes his paws on the side, the scratches the bottom lip of the opening, then the walls outside the litterbox and the laundry room door in front of the box. This routine takes 10+ minutes and is LOUD. He isnt using his claws though, its like a wiping motion.

He does the same thing with his food. He will eat his food and then wipe/scratch the wall above his food dish for 4-5 minutes.

He's not destroying anything, but it is loud, and Blossom doesnt do it--only Billy. I asked the vet, and he didn't seem worried about it. However, the sound is loud enough that it wakes both me and my husband up 2-3 times at night, even with our door shut.

Does anyone have any ideas about why he does this and how I can cut his wiping/scratching time down to less than a minute so we can get some sleep?

Thanks!

The litterbox issue sounds as though the box is too small for him.
As for the food covering thing, it's normal.
Cats (not all) instinctually bury any food they haven't finished in order to 'hide' it until their return.

Box is either to small..or......

Like my Dutchy he is cleaning his paws...Dutchy does this..everytime, and it takes sometime. Our boxes are very high sided, but she uses the lip and walls..and anything her little paws can touch. I have learned to tune it out.

He is not a very big cat. They have two boxes--one is a smaller size, and one is large. It happens irregardless of what box he is in--though he does show a preference for the larger box.

Does it usually last so long though? He is scratching in the box for 10+ every time he goes, and 5+ minutes with the food.