Abstract: A method and apparatus for cleaning a flexible bulk container includes a dust collector having a negative pressure chamber connected through a vacuum hose to a fill spout support chamber to which a dirty container is connected in a substantially dust tight relationship. An exhaust blower of the dust collector is connected through a pressure hose to the fill spout support chamber. An alternating valve connected to the two hoses alternately disrupts fluid flow through one hose while allowing fluid flow through the remaining hose to alternately inflate and evacuate the dirty container connected to the fill spout support chamber. The alternate inflating and evacuation of the dirty container is repeated a predetermined number of times to remove the desired amount of particulate material from the dirty container. A third hose is connected to the dust collector for vacuuming the exterior of the dirty container.