One thing worth mentioning...just the soak is NOT really enough for a big housing....Sandra has been using the Sea & Sea housing for her Canon 5D Mark II...and dives 2 to 3 times per week..or more...for many years now...
The Sea& Sea was NOT getting the salt and deposits cleaned out well enough when Sandra only let the camera sit in the rinse water....This came out 2 years ago at yearly maintenance by Reef Photo ( who are A.W.E.S.O.M.E. by the way)....It was determined, that on getting out of the water, Sandra should use a hose to rinse the camera well, with some pressure, and get all the dials and buttons to have a real spraying where fresh water can push the salt and minerals out....A year later, after a spray at the boat or BHB, and a BIG spray with the hose at home....and the Rinse bucket just being used to keep crystals from forming prior to the hosings...the maintance last year showed the housing was pristine this time, compared to just sitting the housing in the water.