I did cosmetics, specifically sclerotherapy of varicose veins many years ago. I went out to a training course, got certified by the society and started doing it. It was ok, but it was hard for me to jump from a cancer patient trying to stay alive to a middle aged person with no medical problems all concerned about a little spider vein. If you do it, you should do the cosmetics on a different day and train the staff that on this day priorities are different. Maybe even have different part time staff for that day.