I hate recommending a pressure washer because of the risk of washing out sealant but I think it's justified in this case. Only use an electric from a distance and be extremely careful not to hit any fitting, window frame, etc. Rebedding is not a short, nor easy project. I do suggest spending a few hours inside the boat when it's raining heavily so you know what leaks need to be addressed.
Take a pic and get the model of your head. Chances are that it will need a replacement or overhaul, including the hoses. Hoses and the joker valve are the primary source of smells. Hose gets expensive but you can get a Jabsco head for $200. Don't skimp on the hoses. Your partner will never let you hear the end of it if it stinks!