We’ve all been there at one time or another. That odor of rotten eggs drifting up from the head is every boat owner’s headache. Is it coming from the toilet itself? The hoses? The holding tanks? Whatever it is, it’s no fun. The problem is that you can’t have a cruising boat without having at least one, or preferably two, heads on board. Bowing to the trend to make boats more family-friendly (and particularly more friendly to the ladies of the family), manufacturers are packing heads into smaller and smaller boats, even center consoles. The new Hunt 32cc, for example,…