answer:Cleaning a mattress is a hassle, but it can be done, the exact same thing happened to me a few years back. You would need to use a sponge and a detergent (like a carpet cleaner for example), and clean the stain as deep as possible that way. Don’t use too much water, the last thing you want to do is gorge it with water because the next step…is drying the mattress! Ideally, you would simply put it outside on a sunny day with a breeze and wait (which is what we did). Alternatively, you can use a hair dryer, or better yet a vacuum that doesn’t mind water. Hope this helps! :-)