Abstract: A device for cleaning surfaces of chemical contaminants. The device comprises a hopper-like vessel having upper and lower chambers separated by a horizontal partition that constitutes the bottom of the upper chamber; an inverted U-shaped withdrawal tube located within said upper chamber and having intake and delivery legs which intake leg terminates short of the bottom of the upper chamber and which delivery leg opens into said lower chamber; an injector pipe having a nozzle located within the lower chamber and aligned therewith a delivery pipe having its intake end located within the lower chamber, the injection and delivery pipes producing together a pumping effect whereby the decontaminating agent is sucked from the upper chamber and a dispersion is formed in situ.