Binding Waste Water Fixed!
I just wanted to report that a binding waste water valve solution I saw on YouTube really worked!!
On our last trip, our gray water valve bound up so tightly that the plastic handle poped off the shaft. Thankfully, I was able to use pliers to pull the valve out to release the water.
The plastic threads in the handle didn't look too damaged so I screwed the handle back on to the shaft and pushed it back in. When I got home I fretted that night about how to resolve it without replacing the entire valve since we are scheduled to travel again in a couple of weeks. Then I remembered the YouTube video on drilling a small hole in the valve body next to the handle (handle in the closed position) and squirting dry lube in the hole; then sealing the hole back with a small screw.
Well, I tried it and much to my great relief, it worked like a charm. The valve slides in and out very easily now. I plan to do it to my black water valve next and then to lube valves periodically by removing the screws.