I would seriously be much more concerned about the effects of sand on compressors and blades for repeated ops, than landing in the sand (steel mats, mesh etc can manage that for you).
Sand may mean beach - beach means salt water and salt spray. That of itself would be another concern and will raise issues on any aircraft with repeated exposure.
Even with Centrisep Eaps, I think you're still going to see some additional engine overhaul costs, although obviously much better than without it. Does Pall even have an installation for the S76B PT6 installation (not too many S76B variants I would have thought to justify development - curious myself). None of it will help with M/R and T/R blade erosion though (tapes etc just aren't that effective) - ouch!