The cleaning apparatus includes a source of gas under pressure (12) and a source of fluid (14), along with associated gas (26) and fluid (34) chambers, adapted for successive single uses. A user-operated metered valve (22) connects the gas reservoir to the gas chamber, while a liquid pump (30) and a one-way valve (32) connects the liquid reservoir to the liquid chamber. When gas is released from the gas reservoir, it expands rapidly from the valve into the gas chamber, resulting in pressure therein sufficient to open a one-way valve (34) connecting the gas chamber to the liquid chamber. The gas in the liquid chamber forces liquid therein through a liquid line (15) to a connecting point with a gas stream line (13) from the gas chamber.