A diffuser assembly is provided which includes an upper mounting member mountable within a conduit and having an fluid inlet port, and a lower section having a diffuser screen. A plurality of radially oriented cutters are removably attached to the diffuser screen, and the cutters may extend internal or external to the diffuser screen. A first set of cutters is mounted at a first selected height along the central axis of the diffuser screen, and wherein a second set of cutters is mounted at a second selected height along the central axis of the diffuser screen. The diffuser assembly may be positioned in different locations, including within a downhole carrier sub inside a well bore, within a drill pipe at the rig floor, or within a conduit in fluid communication between a mixing tank and a pump.