On Sun, 28 Feb 2010 23:32:07 +0000 (UTC), ShadowTek
wrote:

On 2010-02-28, Bob F wrote:

There are probably "pourable" insulations available. Small bead-like chunks
which will tend to flow to fill gaps.

lol I'd hate to cut a hole for a light switch with something like that
in the walls!

You betcha!

Perlite has/was used in block walls for sound, more than insulation
purposes. Used between condo unit walls back in the day.

Spill the bag when you opened it .... more went on the floor than
inside the block cavity. :-/