I use a similar technique of using sleeping with regular conditioner in my hair as a form of DC. I like to use 1 tbsp
Shea moisture restorative Conditioner plus 1 tbsp coconut, olive or avocado oil. I too rinse it under cold water with my back arched so that I don't get showered with the cold water. Also, prior to rinsing I finger comb hair to make sure it is detangle and if I have a hard time, I may add on top extra conditioner. Does not have to be the same but must be a good detangler.