It definitely works under the following conditions(I have done it dozens of times when a dangus has written on my whiteboard with the wrong marker): 1. You hav

It definitely works under the following conditions(I have done it dozens of times when a dangus has written on my whiteboard with the wrong marker): 1. You have just applied the permanent marker 2. You have a fairly wet dry-erase marker 3. You blot the perm with the dry-erase so as to flush the site with ink 4. Attempt to wipe/remove 5. Do this fast