Here's an update on the rhytidocaulon cutting I have in my cuttings box. It's been sitting in about 1.5 inch of damp perlite in the box, on a heat pad.
It opened the flower bud it's been growing for about a week now, and there are three new buds developing on the new growth tip.
I'm not sure how it's surviving all the water in the perlite since there's no drainage holes in the container, but it seems to like it and the heat mat underneath it all. The temperature in the damp perlite is 98-101 degrees F. I've been measuring it the last few days.