Memory Foam Mattress Topper Cleaning

How to clean the mattress?
I live in a residence (first year in college) and I have a memory foam mattress topper for thin bed. Only one inch thick, foam egg cartons memory at the top then the bottom. Works great, but I have used since last September and probably needs cleaning. I Febreeze a couple of times, but he did. How to clean something like that? I do not think it would be good in small rings we have. I'm also in a bedroom I can not go outside and pipe down and let it dry. Ideas?
Can be washed in a washing machine. Use water cold or warm but not hot. Use a laundry detergent, but no fabric softener. Do not tumble dry. Air dry. If you can hang a line, simply pass a couple of chairs. It should dry in 24 hours. –
Mattress Covers for Healthy Bed Protection



