[pen/Rosie] My family has always used the verb "to foof" (or possibly "fouffe" - the spelling has never been established) for what you do to get ant powder out of the bottle. In fact, the verb often gets repeated to become "I'm just going to foofoofoof that ant-hole."
Possibly cruel, but quite entertaining is pouring bicarbonate of soda solution down the ants' nest - the whole thing fizzes quite satisfyingly and the poor wee ants themselves sometimes exhibit a certain anal effervescence too.