start with a cheap case, any caliber, to test it. Really easy after you have done it a few times.
find a long socket that fits the case. (no need to hold the case, just fit it approximately). Put the socket on a drill.
Then, insert the case in the socket, and rotate the mouth of the case over the propane torch.(canted upwards just a bit so the case doesnt slip out of the socket) After a few seconds, the color of the mouth will change, and then you will see a "color change line" starting to go down the mouth, then neck, then shoulder. (the grayish color of annealed case necks), with a gray/blue line at the bottom.
When the line is just at the bottom of the shoulder, you are done. drop the case on a pan and do the next one.
http://www.youtube.com/watch?v=0FU1udDEw9s
that shows the basic idea.
and here is some info
http://www.6mmbr.com/annealing.html
"Unlike steel, which will be made harder when it is cooled rapidly, brass is virtually unaffected when it is rapidly cooled. Annealing brass and suddenly quenching it in water will have no measurable effect on the brass. "
So you can drop them in water if you want to "prevent" further annealing once you have hit the shoulder".
"When you get the faint blue color and the shine remains on the case, you have everything adjusted to perfection. "
IF you absolutely want an anneal that is 100% the same on every case, you need an automatic annealer. If you can live with an anneal that is "approximately the same and works", you can do it by hand.
Unless you are a 1000 yards champion, you probably do not need a machine I guess, unless you want one. Of course if you are processing alot of cases, often, automatic is faster.
