Cleaning A Playpen??

How can you clean a playpen? I feel like that's a stupid question to ask but I'm a first time mom and I don't really know how to clean some thing properly like a playpen for instance lol. I was thinking to use a damp rag and wipe the bottom piece down but I didn't know if that would make it start to smell like the water mildewy smell and ruin it. It really needs cleaned though, I put her in it quite a bit when I'm cooking and doing dishes while my husband is at work and it's starting to look pretty dirty on the bottom from the snacks I give her in there and just in general dirt from her legs from crawling and such. thanks in advance to everyone with answers or ideas!