Hi
Watch out for bleach, it can create a gas when mixed with other chemicals that can cause serious lung damage. I think Fix is NOT to be mixed with bleach. Read the bleach label for more details. I have used bleach to clean the Developer tray of an old PMT (photostat) processor to remover the silver build up. However the 1st use killed the new chemistry. So I filled with chemistry and left for a few hours to "neutralize" the bleach. So perhaps after a good cleaning, fill the developer tank with water and run, empty and repeat as many times as practical, then fill with Polyester Developer and allow to soak & run for as long as possible. Be prepared that the first fill of Polyester developer may be ruined. Do a rough cost analysis, the time for the extra rinses, potential problems, cost of developer, is it worth the cost of the special rinse. Hope all works out well