Thanks guys for the advice. The smell I presently have is from removing the old sanitation lines and having the holding tank and lines open during the process. I closed off the tank lines while removing the hoses, but still stuck the place up a bit. It may clear over time if I can keep the boat opened up.
"renting a commercial ozone generator for a few days is probably more cost effective than purchasing one for one time use."
For a liveaboard , where the boat is open and ventilated daily , perhaps.
For the older boat that is not in constant use the amazing variety of aromas can be kept sweet. That's why some ozone units are DC powered .