The frequencies were determined by a man called Lloyd Mear, and I bought his original manual years ago. Here's where you can get the updated manual and it tells you a bit about how to use them
https://www.balancingbynumbers.com/user-guide-energy-balancing-by-numbers/
I scanned the Hair page
There are a few there that you could test (or just use). Ask again if you need to know more.
This is awesome! Thank you so much :)
Bookmarking that link immediately for further investigation.