I've used some Kilz primer to cover mouse urine on plywood in one old part of a wall that I tore apart. It worked very well, but I think it was oil based. The enzymatic cleaners that we tried first didn't do much of anything for our problem. (Neither did vinegar, bleach, soap and water, lots of scrubbing, etc.) Kilz does seem to offer water based primers too, they might be worth checking out.