A flushing tool for a perforated tubing in a production tubing string is described. The flushing tool includes a chamber that is sealed at a pressure at or below atmospheric pressure when the flushing tool is in its sealed configuration, the chamber arranged to receive wellbore fluids when the flushing tool is in its activated configuration. A port allows ingress of wellbore fluids into the chamber when the flushing tool is in its activated configuration. A sealing means has a first position when the flushing tool is in its sealed configuration and a second position when the flushing tool is in its activated configuration. An actuator releases the flushing tool from its sealed configuration to its activated configuration by releasing the sealing means to move from the first position to the second position.