I'm late to the party but I'm having similar issues. The urine diverter has a very slow drain that's caused a ton of backsplash around the bucket! Ew! We cleaned the mess and used a drop of dawn, sprinkle of baking soda, and vinegar last week. It seemed on for a week. After several midnight urinating between two of us, we were upset to discover the problem happened again...
After a bunch of research we bought Campa Fresh enzyme cleaner but it says it's a holding tank treatment. I'm not sure if it's the same as drain cleaner but we're broke tiny home dwellers in a rural area and didn't have a large selection.
It says to use up to 6oz followed by a gallon of water. I used about 20 oz down the urinal followed by 3 kettles of boiling water. The drain bubbled a lot. I can see some calcification that moved a little. It started draining but it still seems as if something is blocked. I believe this cleaner may continue working overnight so we'll see.
