Slipcoverings

The dog has taken to oozing up onto the couch or armchair when there's no one in the room to notice.

I say "ooze" because, despite his size (recently analysed as a cross between a Lab and an Irish Wolfhound, but I prefer the Lab-German Shepherd guess), he can silently, slowly extend himself like a snake and wend his way from the floor onto the furniture. At the same time, he carefully avoids eye contact with any human nearby, as though to suggest that he's not actually climbing onto the furniture.

I need to slipcover the couch so that I can throw the coverings into the wash after his muddy paws make contact. I'm thinking of something super-easy, like just using the left-over navy linen or extra ticking fabric I found from a long-ago slipcovering purchase, and making large envelopes for the couch cushions with twill ties on the back to keep them closed.