Imagine this.
In a form of an small electric chain saw, where instead of the chain blades, there would be different sizes of chain brushes. Also different hardness. It could have a chain cover all the way around where only the top couple of inches are showing. That will stop the stuff splashing around.
As the chain goes around into the machine, it could have a crud collector/brush cleaner compartment, that way the chainbrush will be coming back out clean and ready to scrub.
I've been dreaming about a machine like that since I started scrubbing grouts. Over 10years ago. I should just make a unit like that...
Can anyone else picture what I'm trying to say.... I wish I could draw. I would draw a picture- I suck at drawing so bad I mess up a stick figure if I try to draw one...