A pump on the transom is the better way to go, you can get them with deck wash bypass as well. My deck wash eventually failed and it was amazing how much I missed it as even the deckies got used to using it an the clean up once back home was much simpler. Just remember to put a shutoff valve between the pump and the transom as that small pipe will push a lot of water into your hull if underway in a very short amount of time.