Rolf wheels were known for collecting water years ago. They even started putting a small drain hole in the side of the rim. You'd put the hole at the 6 o'clock position and eventually the water would drain out.

I'd put valve stem at the 6 o'clock position and let out most of the air. Then I'd push in the valve stem a little until the water started draining out. It wouldn't get it all out, but quite a bit.