How should I clean the pen brush? June 17, 2021 13:11 Updated To clean, simply wipe the bristles with a tissue. Do not use water. Related articles Is the pen safe for enamel? What if I am unhappy with the results? Does the pen cause sensitivity? The packaging says the product is flammable, can you travel with it on an airplane? Why should I choose this whitening pen? Comments 0 comments Article is closed for comments.