From all the so called "Experts" here in Florida, they say never use ocean, only fresh water, driftwood to mount orchids as you can never really get the salt out of the wood. You really don't know how long it's been in the water to know how deeply its saturated with salt. Hope this helps.

Is there a way to measure it perhaps the salt content of the water after sitting in water for a while?

Is it absolutly imperative that all the salts come out? doesnt it just mean the driftwood will just dry up quicker and it will need a more humid enviroment?

Hi
I've tried driftwood mounts over the years with so so results .Biggest problem was the wood rotted just as the orchid was getting well established.. Not sure about the salt
but would think most orchids will not tolerate it?? I got mine from a "junk/nature dealer and had set outdoors for well over 5 years Decided it had no advantage over cork
had often thought of making a "tree ' out of PVC covered with cork and or tree fern such as they have at the AOS garden. Good luck !!! gary