My experiences (correlates fully with Gunnars on The Remote)
In short about The Remote:
Wash with freshwater after use, inside the gasket.
DONT charge it after rinsed - wait till it is totally dry, open the gasket/flap so sure it dries, or it might "go up in smoke" when you charge.
The long one:
We are talking about "The Remote" which works for GoPro Hero 8 and up, and Max.
The "Smart Remote" works for older heros up to and also Hero 8, it has a lot better range, and you can shut the camera down to save power while going upwind, and turn it on later (most of the time it works, not always), but it does not show remaining battery on your camera.
On this one, corrosion was an issue, and one needed to know how to reset this one, as otherwise it could "die", without being dead.
Did not happen often, and you can google the reset (on both models), it is not written in any manual.
Bugger, as if battery is empty, you can not be sure if your charging isnt fully connected because of oxidation (corrosion) or if it needs a reset - tricked me many times till I found out.
And the goldplated contacts needs a "scrape" or rinse with contact cleaner now and then.
One or two went dead of other reasons, so not as sturdy (electronics not a mechanical issue) and I got a replacement from the shop each time, nice.
Back to The Remote, not the same range as Smart Remote so not as good for a kitecam remote, but works fine for a linecam mostly, and has other advantages like being able to see the remaining power on the camera besides multiple cams can be connected and somehow the "turn the camera on" works a lot better than the Smart Remote.
And one can set the auto camera shutdown to minimum time if you want to save the battery out there for longer non activity periods, as you can not shut camera down from the remote, but as said, the "turn camera on" works quite good.
It has AWESOME battery life, almost no power consumption so dont need to be charged very often
Which is good, because as said, if it has been in saltwater and wet, you WILL destroy it immediately when charging.
If in saltwater and dry, salt might still have the USB-C connector literally go up in smoke.
If rinsed with freshwater and wet, you might also ruin the connector.
The gasket is not a water proofing, more like a protection for "everything else" but not water in our use.
I had one connector "burn" on mine so useless when battery was dead (a lot later - lasts almost forever even if you use it every second day), and bought a new one as I use it very often.
Suddenly the connector started to work again, and I have been able to charge ever since (3 months), so I sold my new one to a friend, it was still unopened just bought it when my battery on the first one was dead, as it could not be charged anymore - but it has worked ever since.
Used over a year now, used every second or third day maybe.
Slight corrosion might occur, but usually it will still continue to work just fine.
As said, if wet or dry salty, you WILL ruin the USB-C connector, it charges quite rapidly meaning considerable current so it can burn and cut the connection(s) and might get useless.
My experiences on these ones, being an Engineer in electronics and mechanics, if it can help someone.
I still use both remotes, as I have kept an older Hero 8 as a kitecam, where more range is needed.
If you take a bit care, they can last quite long, and not that costly (not low cost either) so should be okay if one has to buy a new one eventually.
Peter