Cleaning pack n play mattress.

Does anyone know a good way to clean the mattress in the pack n play? Ours is soo stained already between my little guy spitting up all the time and then every once in a while he will pee while we're changing him or leak up his back so theres pee stains. I wipe it down with a cleaning wipe but that doesn't help. Suggestions?

Pic for reference 🤢

Update!

I took a really warm wash cloth with dish soap on it and scrubbed the mattress down and let it air dry. Voila! Its gone until I can soak it at least!