We are fairly new to rving. We purchased this Rbss and took it out once. Got home and cleaned it good. There is a awful smell that we can’t pinpoint. We have cleaned out the black and grey tanks 3 times. Covered vent pipes, checked roof. Closed it up and when we go back in it’s bad. I have been on my hands and knees smelling every corner inside and out and can’t find it! How do we pinpoint it? Driving us crazy. Thought a mouse died someplace but after 5 weeks wouldn’t that be gone? Thanks