I have a potential use for old gypsum board, and would like to hear your comments on it…..

Basically packing old gypsum board into the stud bays in the interior walls to add thermal mass.
I am avoiding packing into the bottom 1ft and top 1ft of stud bays or any bays with electric wires running vertically.

Also it probably provides some acoustical dampening.

I am also wondering whether it is wise to pack the stud bays in the interior walls adjacent to the bathroom. I’ll use Durock in the wet areas and either a green gypsum or more likely a non-paper gypsum board in the main part of the bathroom. But is it still safe to pack the void with old scraps of paper based gypsum in the bathroom wall voids?

– Mark