What tuning forks are you using and what frequency are they tuned to, if I may ask?

I ask because I got involved with an acquaintance considering the use of frequencies. She found a site that sells sets of tuning forks. As they purported to be critical frequencies I emailed asking at what temperature they produced the quoted frequencies and they replied with some nonsense that temperature didn't matter.

(I wasn't seriously concerned about the working temperature but I wanted to see how much they knew about their products. I told my friend that I'd lend her an oscillator to experiment with different frequencies when she's ready. It's a lot more stable and has a frequency counter attached so she can set it exactly.)

But yes, different frequencies do different things and some parts of the body are fairly sensitive.