I use coir, the ground coconut husk material, and haven't had any problem. It's sold as a brick which gets reconstituted with water.
I haven't seen any evidence of salt injury to any plants I've used it for but, if you're concerned, fill the pot a few times and allow it to drain in between. I use coconut husk chips (CHC) for orchids and just soak and drain them a few times to remove any (potential) salt. My N. x Ventrata is thriving in CHC, by the way.
I've read the salt comes from coconuts that are floated down rivers into brackish areas where they're corralled for processing. I try to picture men hopping from coconut to coconut during the big river drives, but can't quite see it.
Coir has a wonderful texture and I use it when making all my various potting mixes. If there's a problem to consider, it's that the stuff breaks down to goo more quickly than sphagnum peat. I use coir as an addition to bulkier materials, such as sphagnum or perlite or vermiculite, so haven't worried too much about it. It seems to take a year or more, but I would recommend monitoring coir if used as a primary potting material.
Using coir allows us to use an agricultural waste product instead of consuming more peat and I think it's a good idea.