Hey Aussies, I have been using Beauty and the Bees products for over 3 years now, including the shampoo bars. I love them, they lather well but rinse out really easily. I use the Lemon one.
I did notice some kind of buildup however, my hair would occasionally get stiff, thick and stringy, especially at the back where I would have it in a ponytail, BUT, I never used to condition, I was under the impression that I didn't need to while using the poo bars and I thought the condish was making my hair too boofy so I ditched it when i started using the bars. Now I think that if I had have been following up with rinse outs and co washes I would not have had a problem.
I have been co washing for about a month now and in that time used the bar once to remove buildup, it seemed to really freshen up my hair. I will be using it for a second time tomorrow. I think once to twice a month will be enough for me with my current routine.
My hair hates ACV. I have tried it with all finds of dilutions and it always ends up like straw.
So yeah, long time user here, never really noticed a problem with build up until recently though which is odd. I can't rave about these bars enough, they are so handy to take traveling too, you can just slice off a portion to take away with you.
If you get it in your eyes it hurts like crazy, so be careful with that (if you use it on your kids and it gets in their eyes they will certainly let you know).