Yes! . . . there have been reports that "EVCO" (Extra Virgin Coconut Oil) has caused some relaxed hair to tangle. One of my clients can attest to this fact as well. Also, as I look back, when I have used the EVCO as a pre-shampoo treatment, I sometimes found that my clients' hair would become less manageable when it was time to roller set it. Of course, I contributed the hair's misbehavior to "relaxer touch-up" coming due. Now, reflecting back, the coconut oil that I thought was supposed to be a benefit was actually a culprit for tangles.
I found an online list of 122 uses for EVCO from everything from "cleaning agents" to lubricating musical instruments. Apparently, the fatty acids from the Extra Virgin Coconut Oil can coat almost anything. Notice that the Coconut Oil is solid most of the time? Many people prefer to use it on their hair during the summer months when it is less likely to solidify in their hair.
But back to my personal experience with "heavy oil treatments," I have had clients come in with Coconut oil, Ojon oil, etc to pre-treat their hair before their hair appointment. If your hair is natural (no relaxer), then more than likely, you will have "No Problem." However, if you have a relaxed., type 4 hair, the coconut oil may act like a protein causing overproteinizing (overfilling) of the hair strands making it more prone to tangle.
Some natural hair cleansing creams and natural hair conditioners can also become protein overkill for Type 4, relaxed hair.
If your hair begins to have a mind of its own and becomes unmanageable then you will have to clarify it to try to strip the extra protein out, neutralize it with a low pH conditioner, recondition with a liquid moisturizing conditioner (versus a cream based conditioner), and then seal with a smoothing conditioner.
Need some product suggestions? Please see my article on the "Reset Regimen for overproteinized hair."