I think I've figured out that the timing is different for deskwork than it is for housework, though. For housework, I do best with 15 on, 10 off cycle. For desk, 20 on and 5 off seems to work - I consistently worked five minutes past the timer going off for the 15 and I figured early on that five minutes was enough break for me.
Interesting that I operate on a 25 minute cycle. :)
