We have a Bosch WM, and live in a hard water area, the machine collects grey sludge internally somewhere and periodically releases bits which then mess up the washing. Our previous 2 Hoovers never did this. We use calgon (which seems to have made no difference at all) and once in a while I run it empty on max temp to try to clear it out, but it remains a problem.
Does anyone have any suggestions about how to deal with this? Is there something I could out in an empty wash to clean it out more effectively, that wouldn't destroy the hoses etc?