Love this thread, this is one of life's little mysteries that has never ceased to confound me, likewise the draining rack at kitchen sink, we always rinse our washing up so it can't even be residue from washing up water that makes that dirty, the cutlery drainer is the worst thing, so difficult to clean too.
I know none of those jobs will be getting done at moment, I'm banned from downstairs of house, is cos I have long term illnesses and my DH wants to keep me as safe as possible, it's a tad frustrating but it's good to feel treasured. If he gets ill I'll need to access rooms and disinfect things before I can even make a cup of tea but by staying home hopefully we'll both stay safe and he can continue to look after me in the easy he wants to. I'll need to mention cleaning the draining rack etc to him, I know they'll not have been done for over 3weeks now, eurgh. ?