F-stop timing is like fly fishing. A lot of up front resistance, not wanting to let go of what you already know, then trying it, getting over the hump and no going back. Another vote for f-stop printing. It makes dodges and burns more intuitive also.
I saw Fred Picker's video recently (a good deal on DVD at Calumet and well worth watching). He standardized to a series of 3-second exposures which also makes good sense but not my preferred method.
Used timers are cheap. Even if you don't get an f-stop timer, get one with a metronome function so you don't have to watch the clock during dodges and burns.