To point out how determined and strong critters are: Our Raccoon pulled the pattern out of the linoleum and pried the wall paper apart at a seam no one else could see.
Rats got into our heating duct work by gnawing through mortar below the sill plate, which was treated and didn't taste good, I guess.
I've heard of Raccoons figuring out fastened garbage can lids.
And a long list I don't remember right now. They want out of the weather or a nesting place or smell food or sense warmth they will tear the towel out. Not sure anything short of metal will stop them. It won't stop rats. They will chew through flashing and gutters etc.
Likely they would chew through the sewer hose, unless it has some kinda smell bad/taste bad quality and into the tank and up the shower or toilet.