I bought a blacklight to find urine spots on my carpet. I also have Simple Solution. I have to wait until dark to find the spots. There are a lot. I want to mark them somehow at night, so the next day I can treat the areas with Simple Solution and extract with my carpet cleaner. I don’t want to wake neighbors in building with carpet cleaner at night. What can I outline these areas with, so I can see the next day, but will also come out of my carpet?