You can create a spray bottle solution of water and a drop or two of a sanitizing essential oil (i.e. tree tree oil, eucalyptus) for regular use. Briefly spray mat and wipe it down with a clean towel after each use.
Create a solution by adding lemon juice to baking soda. Once bubbles form, add cold water to dilute. Use solution to dab stains/ wipe down mat thoroughly with a clean towel. Rinse towel, then wipe mat down once more with just water. Air dry away from sun.