Stripper or
slut-in-a-
box worker. Mostly you hear the expression from old gomers nowadays. From the old usage of "sling" to mean delivering or presenting, so in 30s
hep jive, waitresses were hash slingers, bartenders were booze slingers, and so on.
Grandma got through the first part of the
Depression slinging milk, but the dairy went bankrupt, so she slung hash for a while, till she found out she could make a lot more at the
burly-q as a tit
slinger.