This is a question I put to Orion Binoculars:

Hi!

I'm considering getting one of your waterproof monoculars, but it says
in your cleaning section NOT to clean ANY lenses with water & soap,
something I do regularly and they come out spotless (to the naked
eye). Do you have any evidence that it destroys the coatings?

Thanks!

***

For us kayakers it seems like the easy thing to do. Binoculars get sea
water and water and soap seems the easy solution. This is the same
method I follow with sunglasses. I let them air dry and come out like
new month after month.