"Her cooking is not clean". Old movie quote. What does it mean?

Old_Cat_Lady

Last night I woke up and put the tv on to an infomercial on omega 3 fish oil capsules. Puts me right to sleep. When I woke up an old, old black and white movie was on. A lady in a kitchen fully dressed with her hair in dipty-do curls and apron. Really old movie.
Her quote to the man "Don't eat at her house, her cooking is not clean". I wonder what it meant back in the days (I"m guessing 1940's). She didn't have running water to was dishes? Soap?
I can't remember the channel or I would have looked up the movie name. It was about a fire station. I swear that was the quote. I couldn't believe it.

HeidiCooksSupper

Context is everything. Could mean she used dirty pots, she was dirty, etc. In another context it could mean "unclean" in the Kosher sense of including unclean animals, mixing meat and dairy, etc.

stevencloser

The meth didn't have 99% purity.

RunsWithBees

Maybe they were talking about Typhoid Mary?