A self-cleaning dosing apparatus (30, 130) comprising: a) a material hopper that is configured to contain pellets of material; b) a feed screw; c) a first material outlet through which pellets of material fall by gravity onto a first end of the feed screw; d) a cylindrical insert that surrounds the feed screw; and e) a motor that is connected to the first end of the feed screw and configured to rotate the feed screw inside of the cylindrical insert to push pellets of material to a second end of the feed screw where the pellets of material fall out of the cylindrical insert; the self-cleaning dosing apparatus (30, 130) further comprising: i) a second material outlet located beneath the first end of the feed screw; ii) a slide gate that is configured to block the second material outlet; iii) a pneumatic piston that is configured to pull the slide gate back to unblock and open the second material outlet; and v) an air nozzle that is located opposite the second end of the feed screw and configured to create and direct a stream of air through the cylindrical insert; wherein: aii) the air nozzle is configured to direct the created stream of air to push pellets of material that have fallen to a bottom of the cylindrical insert back through the cylindrical insert towards the second material outlet, the self-cleaning dosing apparatus (30, 130) being characterized by comprising: iv) a Venturi pump that is located under the second material outlet, wherein: ai) the motor is configured to reverse the direction of rotation of the feed screw to thereby transport the pellets of material located between threads of the feed screw backwards towards the second material outlet; and aiii) the Venturi pump is configured to pull all pellets of material, which comprise the pellets of material that fall from the material hopper through the first material outlet and the second material outlet and the pellets of material that are pushed out of the feed screw and the cylindrical insert towards the second material outlet by the reverse rotation of the feed screw and the stream of air from the air nozzle, out of the self-cleaning dosing apparatus (30, 130), thereby completely removing all traces of the material from the material hopper, the feed screw, and the cylindrical insert. a) a material hopper that is configured to contain pellets of material; b) a feed screw; c) a first material outlet through which pellets of material fall by gravity onto a first end of the feed screw; d) a cylindrical insert that surrounds the feed screw; and e) a motor that is connected to the first end of the feed screw and configured to rotate the feed screw inside of the cylindrical insert to push pellets of material to a second end of the feed screw where the pellets of material fall out of the cylindrical insert; i) a second material outlet located beneath the first end of the feed screw; ii) a slide gate that is configured to block the second material outlet; iii) a pneumatic piston that is configured to pull the slide gate back to unblock and open the second material outlet; and v) an air nozzle that is located opposite the second end of the feed screw and configured to create and direct a stream of air through the cylindrical insert; aii) the air nozzle is configured to direct the created stream of air to push pellets of material that have fallen to a bottom of the cylindrical insert back through the cylindrical insert towards the second material outlet, the self-cleaning dosing apparatus (30, 130) being characterized by comprising: iv) a Venturi pump that is located under the second material outlet, wherein: ai) the motor is configured to reverse the direction of rotation of the feed screw to thereby transport the pellets of material located between threads of the feed screw backwards towards the second material outlet; and aiii) the Venturi pump is configured to pull all pellets of material, which comprise the pellets of material that fall from the material hopper through the first material outlet and the second material outlet and the pellets of material that are pushed out of the feed screw and the cylindrical insert towards the second material outlet by the reverse rotation of the feed screw and the stream of air from the air nozzle, out of the self-cleaning dosing apparatus (30, 130), thereby completely removing all traces of the material from the material hopper, the feed screw, and the cylindrical insert. ai) the motor is configured to reverse the direction of rotation of the feed screw to thereby transport the pellets of material located between threads of the feed screw backwards towards the second material outlet; and aiii) the Venturi pump is configured to pull all pellets of material, which comprise the pellets of material that fall from the material hopper through the first material outlet and the second material outlet and the pellets of material that are pushed out of the feed screw and the cylindrical insert towards the second material outlet by the reverse rotation of the feed screw and the stream of air from the air nozzle, out of the self-cleaning dosing apparatus (30, 130), thereby completely removing all traces of the material from the material hopper, the feed screw, and the cylindrical insert.