A quote from Roz Chast's "Can't we talk about something more pleasant":

"What is 'grime'? It's not ordinary dust, or dirt, or a greasy stovetop that hasn't been cleaned in a week or two. It's more of a coating that happens when people haven't cleaned in a really long time. Maybe because they're old, and they're tired, and they don't see what's going on. It covered everything."

There's a case to be made for grime.

A bit of dirt is unpleasant, but when dirt becomes grime, who cares? Compared to sex, what's grime after all?