Yup. The spawand draws up grit through a fine mesh filter via suction created by drawing a long sliding handle/pol out from the body (It siphons up the water and traps the dirt).
It works pretty good.
Other products that might help are the grit getter, a squeezable bulb that draws the water into it and traps the grit and dirt.
The Grit gettter works while you sit in the tub, the spa wand works best if you stand outside the tub.
Both work well.
I've found that if you are getting a lot of grit and dirt in your tub, it's worth it to find the source of it and correct it. Sometimes, with new tub installs it may be some extra sand / dirt around from the fresh construction site/area around the pad.