Mechanical Whiteboard Cleaner

Which material is the best?
Cotton Wool Cotton T-shirt cloth "Magic" Kitchen cloth Paper kitchen towel Sponge         = Bad = Very Good
How well does our mechanical whiteboard cleaner work?
Moves from left to right Wipes off writing in two sweeps Moves smoothly across the whiteboard
Our surprise finding!
Contact between the material and the board is important. The sponge wipes off the writing better than all the rest because it has the best contact with the board.