Thanks to AJ
Procedure (from the Milady textbook):
Procedure for Removing Metallic and Coating Dyes:
1. Apply 70% alcohol to the hair and allow to stand for 5 minutes.
2. Without rinsing the alcohol, apply a heavy oil (mineral, castor, vegetable) thoroughly to the hair.
3. Cover the hair with a plastic bag and place under a hot dryer for 30 minutes.
4. Remove mixture from hair using a concentrated shampoo for oily hair.
5. Work shampoo into hair for 5 minutes then rinse with warm water.
6. Repeat shampoo steps until oil is completely removed.
Perm lotions and other chemicals applied to the hair may react with other chemicals that have already been used such as compound hennas, metallic salts, progressive colours, home use products etc.
An incompatibility test should be carried out to detect chemicals, which could react with a colour or perm process used by professional hairdressers.
• Protect the hands by wearing gloves
• Measure 2 fl.oz liquid hydrogen peroxide 20 Vol plus 2 drops of household ammonia (ammonium hydroxide) in a non-metallic bowl.
• Place a small cutting of the hair into the liquid.
• Watch for signs of bubbling, heating or discolouration. Any of these signs will indicate that the hair contains incompatible chemicals.
• The hair must not be permed, tinted or bleached if any chemical reaction is present in the hair.
There is no recognised method of removing incompatible chemicals from the hair. The client should be advised that cutting the hair until all the hair containing these types of chemicals has been removed