So I've just spent the day firmly roller-ing the popcorn insulation of my trillium
with a 1/4 bleach to 3/4 water solution...who knew you could clean insulation with a paint roller!? Worked great, a couple little areas needed a little rub with a cloth as well.
My research at paint, RV and marine shops led me to ELASTOMERIC paint. It's used for vinyl seats in the marine world. It's highly elastic, hence the name. It's available in a spray can for $16 a can
but I finally found it was available at a paint store for $50/gallon, and found a paint guru who knew how to paint with it! And it can be tinted and is mildew resistant! Haven't tried it yet, but it seems to be the consensus...
Hope this helps...