A quick way to clean the upper layer of your mattress is with
a spray consisting of one part alcohol mixed with two parts
water. Vacuum your mattress and then spray it with the alcohol
solution and let it dry. The alcohol will disinfect the upper
layer and kill any bacteria that are making it smell bad. If you
have any essential oils handy, put a few drops in the solution
to also make it smell fresher.
Incidentally, there
are not pounds of dead mites and skin on the mattress. LINK