tranny flush...

Well I managed to somehow get water in my transmision and would like to do a flush. I've done a little reading on it and the majority of the shit I read says to disconect the cooler lines and put the pick up line in a clean gallon jug of atf and the return line into a empty jug, empty the pan put it back on, add atf through the dipstick hole, start the motor and flush making sure not to let the tranny run dry. Is there a better wat besides going to a shop and having it done?