Receiving a blowjob in which the giver uses so much teeth, it's as if they are attempting to dredge the flesh from the penis, similar to a dredge scraping the bottom of a waterway to make it deeper.
"Dude when she went down on me it felt more like a dredge job than a blow job."
"That dredge job left my penis feeling like I made love to Edward Scissorhands, or a food processor."