+1 on the dishwasher, take note of the gay pensioner's first line though
i got busted ,left a seat in there
you could also try servisol switch cleaner the oil based one not the isopropal one spray it on the grubby bits and let it soak in a bit should bring the dirt to the surface done this on white set prior to the long cycle in the dishy
EDIT that auto name change fookin brill pmsl