Nick Maclaren muttered:

Nuts. The gimmick freak in my house is my wife. I am old fashioned.
A stiff broom, a handful of sharp sand, some water with washing up
liquid in it and SEVERAL beers.

Cheaper, needs less space to store, better for you, usable in areas
with hosepipe bans, less damaging to plants etc.

Or cars, a neighbour got one and his pressure washer made all the gravel fly
up and chip off the paint work of his new Mercedes in the drive ;o)