I know because I became very sick many times.
I know because I got into real healing myself. ( http://www.eczemacure.info
)
I know because I met many real healers along the way to cure myself.
I know because I'm now the family healer.
I know because in my search for higher learning I found and chose Barefoot.
I know because it takes one to know one.
I know never to trust anyone blindly with your personal healing. Read and listen to what barefoot teaches and adapt to your own personal needs. Self experiment. Know yourself.