On the topic of the juniper, I would guess that the heating to 300 degrees would cause the oils and other volatiles in the wood to evaporate out. Might be worth trying on something not too valuable.
I’ve got a Restrepia brachypus that has a few offshoots that are begging to be their own plant. Maybe I’ll put one of those on juniper with a bunch of sphagnum and see how it does.