I've been a few Wendy Murdoch clinics and would go again. I love Feldenkrais work. And I like what she does with the horses. However, you do need to have some appreciation for what she does as it's very subtle work. If you have enough body awareness or want to develop more body awareness, then I highly recommend her clinics.
I did google. I found her website, and I googled the somatic education stuff she does. I didn't find anythng that really explained how she taught dressage or riding but I did find lots of fancy talk. I also didn't find anyone that had real life experiences with her but were not being promoted on her website. I did find a video series of her instructing a man on a western horse in a 12 X 12 foot area in a demo.
I've worked with Wendy many times in the past, and would love to have the opportunity to do so again.
Her lessons are all about using your body in the most correct and comfortable way that is the most beneficial for the horse. She'll teach you how to position every part of your body in a better way, and then have you go back and forth between the "new" optimal position and the "old" position that you and the horse are used to. By doing this, she shows you how much of an influence the littlest changes can have.
You'll probably be a bit sore by the end of the ride from using muscles that you didn't know existed, but your horse will be so comfortable and moving very well.
I think you'd be much better off spending the money on a really really good dressage instructor. WM told me that my horse's stiffness was mental, and to smack him and use a harsh rein aid to correct him everytime he stiffened. Later on I found out from xrays that the horse has bad neck arthritis, hence the stiffening.
Needless to say I felt so terrible for doing Wendy's crazy stuff.