Detail Guardz Dirt Lock utilizes the motion of your hand to engage the Dirt Lock's turbine induction system. Once you pulse your hand in the bucket, the water is dramatically sped up by the shape of the jet turbine.
The dirt is then cycled through hundreds of tapered Venturi funnels and is further sped up again. This shoots the debris underneath the screen and out of harm's way, without a way to re-enter the clean water.
Any small particles that made it through the openings hit the tumbler system and are pushed back down to the bottom of the bucket.
In short, every time you pump your hand in the bucket you are cycling the dirt underneath the screen and replenishing it with reusable clean water.