How to remove the flux residues and solder balls? Ersa can help!

Lots of problems will appear during the PCB production, and the flux residues and solder balls availability is one of them. The flux residues and solder balls will exist when the PCB leaves the liquid solder, the flux residues and solder balls are soldering defect that may lead to short circuiting of the produced PCB board. How should were move the flux residues and solder balls on the PCB board?