I am a new sailor and am looking for a used boat. I looked at only one boat and it had a marine head that really smelled terribly. It had a holding tank and the boat was from ''74. I have several questions now 1) if I get a port-a-potti isn''t that a nasty process to clean? 2) if I get a flush type toilet do I need to have a boat with a holding tank facility built in or can I put this type of toilet on any boat?