A healthy diet in general and exercising. Also, Oyin Juices & Berries. It's not a growth aid but I think all the herbs in it really brought my scalp to it's optimal health, which I'm sure helped the follicles.
It is not what I have used but what I havn't used. And it is not a product at all.
A comb.
I don't comb my hair anymore, so I don't see hair all over the bathroom
The hair stays on my head!
Not a product exactly, but a better diet! I notice when I eat more protein (I''m a vegetarian so like, cottage cheese) my nails grow at a much faster rate and my hair seems healthier. Like, I have zero need for an a protein treatment.
To hair growth: nothing! what helps me retain length is leaving my hair alone! that, and the vitamins, which you said don't count
i will say i do enjoy using Nexxus HydraSleek conditioner as a leave-in; it makes my hair soft and easier to comb. but i can't say that a single product has helped my hair to grow, or any product for that matter. i do have a loooong list of products that have helped me manage my hair better, though.
water (drinking it and rinsing my hair daily)
shea butter and coconut oil mix (keeps my hair moisturized so it stays soft)
protein(great to help my hair withstand breakage that i may have without it)