4. Apply the bleach to your mustache area. The cream should come with an applicator, but if it doesnât, use a popsicle stick or put on gloves and use a finger. Be very careful not to get it on your lip itself or near the delicate skin in your nostrils, which can cause your skin to react. Don't go in the sun for 24 hrs after waxing to prevent your upper lip from getting a dark pigment. 2  If you happen to be a girl that has enough upper-lip hair that you feel you must do something about it, consider using tweezers to remove the hair. 3  It is an easy process to master with just a bit of practice.