I don't think that's true at all. I make a conditioner and I use it both as a rinse out and leave in. I do however rinse it all out and make sure to get it all off my scalp, and then apply a little as a leave in like I would a moisturizer, section by section. There are lots of ladies who use regular conditioners as leave ins. In fact there are some condishes that the manufacturer (oyin) recommends as a leave in as well.