Yup, the key is, with all the CFI training, you are being taught to teach. While I may be able to relate a bit of stuff after a number of months at this, I can see where having a couple of years, and some time, helps give more pointers to the new CFI in training.
Like I said, anyone can do the training. It is the endorsment that matters though.
And again, read the part 61 reference carefully. It says that an examiner _MAY_ allow the endorsement to take place of the spins. I know the DPE on my field, who is allowed to do the initial CFI checkrides, said he picks every 3rd or 4th, I forget which, and tells them to bring a spinnable aircraft to the checkride.
My spin endorsment was a couple of days of dual. 1.5hrs each or so. First day, it was another intro into spins (had done a few a month or so before that). Then repeat to get comfortable. Along with a number of situations that students may bring up to put a plane into a spin. Another day of the same, with a refinement of recoveries, and talking through all phases of the spin as it happened. Was done very well. Other than a couple examples at first, I did all the flying (we did have chutes on, so on the way back, instructor did a couple of rolls on the way down back to the airport, as I was dialing in the ATIS. Went out for a day after that by myself, to make sure I was comfortable with the procedure and talking through all phases. Only thing more I want to do, other than more spins /ubbthreads/images/graemlins/smile.gif would be to sit in the back seat and do them from there. But I'm not teaching in tailwheel at this time, so that'll come.
Kinda fun letting a student get into a 1/2 turn or so if their stall is a little sloppy, and talk them through the fix. Especially fun in a PA38 /ubbthreads/images/graemlins/smile.gif The few times it has happened, I have always had a comment on the ground from the students at how calm I was. I think getting a good few hours of spin practice in, feeling like a crazy person talking to myself outloud, really did help.