I have no idea! I didn't see any plant pot toilets, but then, I wasn't looking. The first one is just before Glaisdale Station.. Here's the train's bridge, too
The second one is between Westerdale and Kildale in the middle of pretty bleak empty moorland, so I can't imagine plant pot toilets there.
They're both at the bottom of climbs.. But there are a fair few of those round here.