Clean with detergent and water...
Do NOT use bleach, Lysol or any "sanitizing" or "antibacterial" cleaning products. Let the area dry out to no more than barely damp. Then spray every surface where waste could have gotten into, behind or under liberally with K.O. holding tank treatment (you can get it at WM, B/US or order it here). It's live bacteria product that will "eat" the remaining odor-causing spores. Do NOT rinse...just let it dry, leaving all hatches and lockers open so that plenty of fresh air can circulate--even put a fan where it can add more air--for 24 hours. That should take care of any odor permanently. If you still have odor, you missed a spot.