Not sure that it would take off - a brand new housing for a camera that may have limited appeal... i think that modern controls are ergononmics have a lot more to offer than the rotatry dials on this camera. i think that you will buy it because of the way it looks rather than functionality?
I rinse mine with fresh Water and maybe a quick rinse in a tank, but never leave it as you can never trust anyone to look after your gear as well as you. in addition i have seen people try to remove housings from crowded rinse tubs by electrical sync cords etc. a rinse in fresh water does not harm and neither does working the buttons. i never coat mine with anything and just relube the main orings prior to each dive, more to check them as even in storage they are lubed in their own zip lock bags to prevent drying.
When diving in highly saline water i take extra care. In the waters of the gulf and Western indian ocean the level of salinity is extremely high. In this environment i always tub soaked my cameras after a weekend or even a days diving more because i am concerned of abrasive salt crystal being in contact of the shaft and scoring a sealing surface. At the pressure a housing works at probably not really ever an issue, but on one of my housings i have seen damage on not the shaft but the aluminium bodyinside the shaft bore - from salt - either as corrosion or physical scoring -not sure. As the air temp was around 42C i am inclined to think that heat, Salinity and Ph might have been the combination to have caused weeping across the seal?
So for me that rinse is removing salt (appearance?), cooling the housing and also ensuring that we are at a neutral Ph balance... and the last thing is that means that you are looking over your gear prior to the next dive...