Oxyclean and water in a spray bottle. Spritz the mattress and scrub with a clean brush, blot with a clean towel and let air dry. Works terrifically.
Thank you so much
Here are some hometalk ideas for you Clive- https://www.hometalk.com/search/posts?filter=cleaning%20mattress%20stains
Hi Clive, here's some help! https://www.hometalk.com/2600394/how-to-clean-a-mattress
if the stain is from body fluids you can try spritzing the area with hydrogen peroxide. Works on laundry, so might work on mattress.