I just did this, after reading some of the thread. I decided to try it with a pea sized bit of melted coconut oil and a shampoo I had around, that does contain sulfates. I liquefied the coconut oil in my palm and added the shampoo, mixed them, then shampooed my hair. I rinsed and followed with 1T acv
in a large tumbler of water, then rinsed that out. Scrunched out most of the water with a towel, combed through my hair and did not add any products. Sat under the bonnet dryer 10 minutes, my hair dried more quickly than usual.
I finger styled and brushed my hair a little, after it was dry.
My curl pattern is looser, smoother,no frizz. No clumpy spirals like I usually have with gel, more like beachy waves, and lots of shine. This reminds me of when I used to set my hair in hot rollers.
I'd say go ahead and try it if you'd like a looser curl and a smoother look for a change, without damage.
Here is my usual hair with CG method.
Here is my result today with the oil shampooing, no products added.