@Alymon, you can always do a test with henna.
not mine of course. i'd get fired ... hold on a minute ... . .dives into henna research..
....Designs last from one to three weeks on the skin, depending on your body temperature, skin type, body chemistry, lifestyle, and where the henna is applied. The average person gets a stain that lasts 10 days to two weeks.
... ..... Swimming in chlorinated water such as pool-water, soaking in a Jacuzzi, washing dishes, and doing housework or strenuous activity like rock-climbing or yoga can accelerate the fading process. Exposure to household detergents and bleaches will also fade it, but you should never apply these strong chemicals directly to the skin. Your best bet is to soak in a Jacuzzi and gently exfoliate your skin once or twice a day, using a loofah or other scrubbing cloth. Henna is permanent on the hair and nails until they grow out.