You can deal with the issue any way you please, it's your boat and those who disagree honestly CAN be told to "put a knot in it." Captain's Perogative.
You may be able to make the point by simply saying that anyone who misses the bowl will be invited to clean out the entire head and that if they really don't want that job, they can think about doing what the skipper does and SIT DOWN.
Or, you can try adding a simple piece of equipment that doesn't get the credit it really should, a "kneeling board". This is simply a large board, like a 2x12, with two u-shaped cutouts on one edge. You install the board in front of the head, so a male can squat down, semi-straddling the bowl with each leg (below the knee) resting in one of those cutouts. (It's similar to the position you'd take when sitting in a Balans chair.)
No need to drop the trousers & foulies, no need to sit, and Real Damned Hard to miss the bowl.
If someone still misses the bowl, you can take the kneeling board and whack 'em over the head with it.