hi there.. i dont think you can clean it off.. as it is an inburnt stain.. as it were. you can clean it.. but not be able to remove the actual discolouring
i have the same problem on my wash m/c
i have tried everything..Bleach.. soap power-diluted, vinegar, jack daniels... :o/ and tooth paste... to no avail.. but at least it is clean.. so it dont maek the wash m/c smell.
the only thing i have yet to try is some coke cola dabbed onto it.
jim spence, December 2007