A pipeline scraper, a cylindrical, plug-like device equipped with scraper blades, rollers, and wire brushes used to clean the inside of a pipeline of accumulations of wax, sand, rust, and water. When inserted in the line, the go-devil is pushed along by the oil pressure. Also a missile dropped into the well bore to detonate an explosive charge or to jar a downhole tool into operation.a scraper with self-adjusting spring blades that is pumped through a pipeline to clear away accumulations and deposits. to drop or pump a device down a borehole, usually through the drill pipe or tubing.