I've seen resistant but take any and drop them in a cup of water overnight and they are dead later.
I think cheap wired earphones are best for this. I can't imagine you buying 50 buck or higher wireless due to water damage issues.
I am moving to south east Asia soon, for a business. I will be outside the most of my time and it is quite rainy over there. Just need some good waterproof earphones. Please help!