Wish I had the chance to try the XClear. I ordered it a month ago from the UK and it never arrived. No correspondence from them for tracking info, refund, nothing.
So I had to file a claim with PayPal for a refund.
If you watch Sam Lights channel, his recommendation is to just lick the lens with a good amount of saliva and do a quick rinse. Same thing that works with a diving mask which works well, so I'd say it's a good solution over anything else.
I have these on my GoPro and they worked great for a few sessions and it is definite better than without, but water drops still happen. I still need to pay attention and lock the lens or wipe it from time to time.
I ordered more than a year ago and ordered other things from them as well. Everything did arrive but some parts took a few months.