I have been working to eliminate the obnoxious odor from our "new" Oday 34. I started by replacing all the (original ?) hoses and the head itself. The 15 gallon plastic holding tank (which I believe is original) is under the v-berth, and the sails that were stored under the v-berth reek, and the v-berth cushions smell none too fresh. This week I have ordered a gallon of KO, as well as a copy of "the book", but I question whether I am going to be able to eliminate the odor without replacing more stuff. I have sprayed the ENTIRE area under the v-berth with Clorox Clean Up, let it sit for 20 minutes and rinsed it well with fresh water. I also did the inside of the forward lockers and bilges. I also sprayed all the cushions with Febreze. The cushions in the main salon and quarter berth seem to be fine, but the foam and covers from the v-berth cushions have a lot of odor. I washed the v-berth cushion covers and all the sailbags on the sanitary setting on our washing machine (2 hours with water heated to 153 degrees), and hung them outside for a day in the sun, but they still have some odor. I have two questions at this point. First, I am most concerned that the walls of the holding tank itself seem to smell - even after washing with the bleach solution. Is it possible the walls of the tank have absorbed the odor - and if so will it be possible to remove it? I did notice that although the tank has two vents, they are connected with a Y before exiting the boat, so I will be working on splitting them to two separate through hulls. Second, I hate to waste a $50 gallon of KO on the foam for the v-berth cushions, (which are otherwise in great shape) if I am going to end up having to replace them anyway because the smell doesn't come out - I realize each case is different, but is there a pretty good chance of success with this method? Thanks for any advice.