Abstract: A method for cleaning teeth by abrasive oral irrigation with a slurry containing a granular dentifrice composition. The dentifrice composition is gravity fed to a liquid reservoir of an oral irrigation device of the type that provides a pulsed, liquid jet stream, and forms a slurry within the reservoir. The slurry is pumped from the device and applied under pressure to teeth and gums. The composition includes a particulate baking soda having granular particles with major dimension in the range 10 to 60 microns, and a flow agent in an amount sufficient to ensure smooth and continuous gravity feed of the composition into the reservoir. A method for making the composition is described.