Just a thought, I get really frizzy up top if I use Yes to Cucumbers Low Poo and I don't put any conditioner on top afterwards. I have to use a rich conditioner (Curl Junkie Argan & Olive Oil) all over and if I don't, I get that frizzy top that you are talking about.
Even lowpooing roughs up our hair and dries it out. I have been alternating lowpooing and cowashing and on the days I cowash I use the lightest conditioner I have just on the lower half of my hair.
I know a lot of people love Tresemme Naturals conditioner, but it made my hair feel gross afterwards. I guess I'm turning into a product snob
Could it also be a build up of shea butter from the moisture retention poo?
Have you ever tried Biosilk Rock Hard Gelee?