unexpected dendro division?

[farm]

I accidentally bumped a dendrobium hybrid and knocked an old pseudobulb off of the rest of the plant. It has some roots sticking out of one end, which makes me think it might be able to move to a new pot. This is my first dendro and first attempt at division. The main plant is in some fairly coarse (3/4"-1" or so) red lava rock, which doesn't strike me as the best medium for division but I'm coming from a place of ignorance here. Does anyone have any advice to offer on how to proceed?

Thanks in advance

[Fairorchids]

If you have some fresh spaghnum moss, place the bulb in a small clay pot with all moist moss. Put it in a clear plastic bag and place it in a shady spot. Check after 6-8 weeks to see whether it has started a new growth.

[farm]

That is exactly the kind of advice I was looking for. Thank you!