Biofeedback Therapy

Anybody have any experience or know anything about biofeedback/neurofeedback therapy? My husband took me to see a woman located here in Houston yesterday for a consultation. Despite her PhD, I thought she was a complete quack. She kept going on and on about how the medicines I was taking were toxic and poisons, and even commented that we shouldn’t take antibiotics. I believe very strongly in complimentary medicine, but she was claiming that this thing called “Nexalin Therapy” and the biofeedback could cure my asthma, and that once I got all the toxins out of my body my mind could heal itself, but never once mentioned anything about the neurofeedback actually helping the vertigo. My husband is still insistent we try it. What do you guys/gals think?