Strip the mattress and wash all bedding
Vacuum the mattress surface
Blot any fresh moisture with a clean dry cloth
Mix equal parts white vinegar and water
Lightly spray the stained area
Blot with a clean cloth
Sprinkle baking soda over the stain
Let it sit for several hours
Vacuum up the baking soda
Mix hydrogen peroxide, baking soda, and a few drops of dish soap
Apply the paste to the stain
Let it dry completely
Vacuum the residue
Repeat if needed
Use an enzyme cleaner for sweat or urine stains
Test any cleaner on a small hidden area first
Avoid soaking the mattress
Let the mattress dry fully before remaking the bed
Use a fan or open windows to speed drying
Protect the mattress with a waterproof cover afterward