Take a look partway down the page on this
AOS article, at the tail end of the Potting Media section and the Repotting section. The situation described in the article isn't an exact match to yours, but I think the info would apply to your plant if I'm imagining it correctly based on your description.
I haven't done what you're thinking about doing because the opportunity has never presented itself and I agree with the others that if this orchid is very special to you, proceed with caution. Otherwise, I'm also someone that enjoys experimenting on plants that no longer bring me joy in their current state. The worst case is the plant goes into the compost pile and you learn something from it.