I’ll go first. After your turn the water off in the shower but before you get out, use your hands to wipe off any standing water on your body. Maybe even give your legs a bit of a shake. This way, you won’t drip nearly as much when you get out, keeping the floor and your towel drier.
I’ve had both H450 and HD458, had the same issue on both of them, though as you note only on one side. Apart from that and them repeating “connection lost” forever, they are great headphones.