Combine all the ingredients and whisk or blend well (I used an immersion blender). You may have to heat the coconut oil slightly to soften it. The Epsom salt will still be somewhat gritty but will dissolve and work in to the hair once applied.
Over a sink or shower, massage the oil through the hair and scalp. Put a shower cap on (or old towel) and leave on for up to 30 minutes.
In the shower, rinse well, then shampoo.
If hair is still oily after washing, massage a small amount of baking soda through the hair to remove or use dry shampoo after the shower.