We visited an orchid/butterfly farm in Thailand some years ago and they showed us how they treated cuttings.
They used those flat quarter bottles, used for spirits and put some damp, not wet, compost in the bottom, added the cutting, replaced the stopper and left for three years.
Smashed the bottle, to get the cutting out, and potted it up.
I told a Thai who owned a restaurant, I would love to try this and she kindly gave me two cuttings from her garden when I left.
I followed procedure and left the bottles on a west facing window sill. They did fine for over a year. Then one day it was exceptionally hot and my orchid cuttings cooked.
I only used moistened multipurpose compost because that was all I had at the time. It was just something I wanted to try to do.
I do not know if that information is helpful but thought I would tell you the tale anyway.
