The word comes from two bases, Fuck and Hoe. A Fuckhoe is a hoe, broad, girl, biddie, slut that you fuck in your extra or spare time. A good time to have a fuckhoe would be at lunch break for example.
"Hey Brady did you and Woodsy have a 3 some with that fuckhoe at lunch yesterday?"
"Ya man, she's kinda getting to be a Dusty Mutslut, I'm thinking i should find a new one.."