A quick way of getting rid of musty smells is to find a large
plastic container with lid which is big enough to contain your
padding and a big bowl of fluid.

Fill the bowl half way with water and add two spoons of ammonia;
place in container and add the padding to container (_not_ the bowl)
ensuring you don't wet it, close container and leave overnight.
The smell should be gone.

A tip: vacuum the padding before 'fumigating' with the ammonia and
if not possible shake out well to get rid of dust.

Renaissance Le Corbeau