This might work with sand. When I was using sand, I could just shake the table by hand to erase.
I have tried a vibrating motor with baking soda - no dice. Won’t even budge.
Personally, I don’t feel a need to level the sand/soda. The next design goes right over the top. You can always print a “wipe” like a spiral or one of the wipes generated by Sandify if you want a clean slate.
If you actually do get a vibrating eraser working though, I’d love to see it!