Different strategies work for different people. I've found I can't pick up more than an hour or two worth of material a day before I start to hit diminishing returns. The longer I press on, the less productive that time is.
I think an hour or two a day is ideal. Work through a single tutorial, finish a chapter in a book or watch some screencasts then implement what you learned. Build a bunch of toy apps that will be thrown away using what you learned that day. At first, you'll start out just doing some command line stuff.
I think most people learn Ruby and Rails at the same time. I personally found that I got more out of it if I focused on Ruby first (a couple hours a day for a couple weeks) then went through some Rails stuff.
I think the "Sweat Lodge" technique is flawed, because it presumes that you'll eventually stop learning. I think it's better to get in a habit of learning a little every day. You're always a work in progress, and you're never "there", so it probably doesn't help to try to speed the process up for getting "there".