Rob, it's on Spa Docs site RHtubs.com But I'll be D@mmned if I can ever actually find it when I am looking for it.
I follow the "intent" of his method, but not exactly.
The main thrustfor me is to raise your Cl to 5pm after soaking to sanitize the spa. The chlorine should drift down to very low levels (less than 3, more like 1 for me) by the next day. This way you keep the spa clean, but do not soak in heavly chlorinated water. It works well for me, and many others report great results too. I'd recomend giving it a try.
I disagree with the statement "you should always have an acceptable level of residual chlorine (3-5ppm) when using your tub". I don't belive it's necessary. I think many state health codes require these levels for public and comercial pools and spas, but a well maintined private hot tub, i don't think it's needed.
Funny though....I keep my pool at 3-5 pmm constently and am happy. But if soak in the hot tub at those levels, my skin gets irrated. Could the heat be the key?