Just follow all the good advice here on cleaning, and keep those cameras facing down when you unmount those lenses. Then it is straight forward to cleaning those mounting surfaces.

And to the one who said,

"I NEVER get any of my equipment within a 100 miles of the conditions you described. Sand is the absolute worst thing you can get near your camera.
Lesson learned?"

I say , no risk, no reward. I have made some of my greatest. most impactful, and award-winning shots in bad weather and challenging conditions, and my gear survived with proper preparation and care before and after the shoot. That is the only lesson. Keep pushing and challenging yourself and your gear to get those special shots.

If you just want to shoot from your armchair or only shoot in nice weather, your photos will always be just safe shots. LOL

Not for this professional, who has shot in the dead of the worst winter blizzards, in hurricanes, in extreme ocean shoots (above and below water) , sandy beaches, and sandy desert environments, in steaming rain forest jungle war conflicts, and so much more. Gear is just a tool to be used. The image is what matters and what is lasting.

Cheers

Easier than you would think. Wind and sand is to be avoided at all costs. If your shooting on the beach and no wind, that's fine, but with the sand blowing around, not so good.
I worked in a large camera store (unnamed) when a teen ager and saw first hand the results of sand and wind. Lenses are basically the same and sand WILL get into the lens, it really does not matter if it reaches the gearing, it is in the lens and will start to grind and scrape, both of these sounds should be kept out of any lens. Agreed?

Was on a Nikon holiday and got sand blasted a couple of days. Got sand in my hair, behind my ears, inside my shirt collar, inside the pockets of my rain jacket, and of course my D850 and D7100 got exposed as well. Where I was at had three days of "hazardous seas marine advisories". Afternoon winds 20 to 30 knots, gusting higher at times. Great wave action, at a price!!! Have not unmounted the lenses from those bodies yet. At night, in my hotel room, I used a very lightly dampened clean face cloth and wiped down the exteriors of cameras and lens bodies as best as I could. Any suggestions moving forward? Upon inspection my equipment looks to be clean. My concern is the lens mount area on both Nikon bodies.

Was on a Nikon holiday and got sand blasted a couple of days. Got sand in my hair, behind my ears, inside my shirt collar, inside the pockets of my rain jacket, and of course my D850 and D7100 got exposed as well. Where I was at had three days of "hazardous seas marine advisories". Afternoon winds 20 to 30 knots, gusting higher at times. Great wave action, at a price!!! Have not unmounted the lenses from those bodies yet. At night, in my hotel room, I used a very lightly dampened clean face cloth and wiped down the exteriors of cameras and lens bodies as best as I could. Any suggestions moving forward? Upon inspection my equipment looks to be clean. My concern is the lens mount area on both Nikon bodies.