We loaded ours up with #1 and #2 on our last trip to central Nevada. At some point about 5 days in the van started to get pretty rank especially after we moved camp. Sometimes it smelled like the potty but others more like rotting broccoli and sausages, which we just happened to have had for dinner a couple nights back. It wasn't even that hot outside, so we were perplexed. When we got to Tonopah we stopped at Tonopah Station RV Park to do my first field empty of a fairly full porta potty. They are used to dealing with big RVs with hookups. When I told them I needed a restroom for it they told me there was one in the back, which I was glad about since coming in through the front lobby would have been kind of uncool on my part. I turned on the vent wishing I could lock the door but it was a 3 holer. By the time I got done I was happy to slip out the back but sorry for the next guy to go in there. I can take a lot of olfactory abuse, I guess, but I usually wear a heavy disposable hardware store mask I stash under the bench seat to help out. I think the porta potty issue was a less than perfect seal on a big load that was burping as we changed elevations. I've since cleaned it out carefully and will try the light coating of coconut oil on the diaphragm as well, along with the magic blend in the holding tank. We left Tonopah but somewhere north of there something started to smell bad again. We put the whole potty in large garbage bag, but an intermittent smell persisted. It was not until we got home to Salt Lake and I drained the sink holding tank out the side that I got a whiff of nastiness that had apparently been brewing in there for days; thus the broccoli and sausage odor. So my lesson is to empty the potty more often as well as draining and rinsing the grey water tank more frequently on the road.