Yak.

If your mattress is 8 yrs old it has doubled in weight.
weight is from yrs of dead skin  sweat residue  mites. your going to lay your head in what. aw fabric fresher will make bed smell good but your lungs also fill with waste/bugs from old matress.
I have air " select bed" mattress.
1 of my bds have 2 seprate controls. 2 n 1 mattress. the top pad covers both individual mattress, that make a whole. I take top pad to laundry mat. can't do that with reg mattress. I slep on twin size select air mattress that has control. most of time I like number 7 setting. slightly firm, and when I want to feel like I'm snuggle ing I set the setting to 4. With the selection bed controls. we can adjust mattress to firmness r softer level that we want without tossing n turning at night, wishing that we had brought a different mattress. I'm retired as Adm of CRCF.  I don't work for " select bed/mattress " nor do I to my knowledge know of anyone that works for select number bed.
inside the topper of cover sleeve is the actual air matress. mine has think cloth on the rubber mattress itself. I use damp wash cloth n go over the inner mattress. I set it out on my patio to dry. I also spread padding out on patio to air dry. after items are dry I spray ea with a water repellant sealant.
When you flip your mattress twice a year,Have you noticed that your matress seems to get heavier every yr. r u now  imbarassed, lol