Have you used heavy gaged aluminum tape to seal mouse holes? Would that work to keep a mouse from chewing through over stuffing steel wool?

There are many solutions to this, some more optically elegant than others. My first choice would be an expanding foam, which builders use to fill in irregularities. Even if it is a large cavity to be filled, you can still do it in a series of layers. Another possibility is to use a board either side of the pipe, each with a semicircular cutout for the pipe. Finally you can use car body repair techniques with aluminium mesh and fibreglass.

thanks for the answers so far! I thought I should provide a little more info of my situation to help. the hole they are coming thru is a large square hole in dry wall that a 2 inch pvc pipe comes thru. plugging it up is not really possible since the size it too big. that's why I was thinking the aluminum tape cuz it can act like a metal plate with a couple layers. the wall could not support concrete unfortunately.

Mice and raccoons went after the insulated AC pipes in my brothers house in a southern US Atlantic Ocean area. They repaired it with HD aluminum tape. It's no way permanent.

USELESS ! MOUSE'S TEETH CAN BIT THROUGH THIN ALUMINUM EASILY, PATCH THE HOLE WITH CEMENT IS THE BEST WAY.

MIX THE CEMENT WITH BROKEN GLASS HAS THE BEST RESULT.

OR LET THE ALUMINUM TAPE GLUE WITH BROKER GLASS POWDER PIECES, AS MOUSE BIT THE TAPE,GLASS CUT MOUSE'S MOUTH. CHECK NEXT DAY IF BLOOD SHOWS ON TAPE.