Gryphon,
Battery memeory like you are describing is no longer a problem with modern Nicads. Nicads have improved quite a lot over the last 10 years, and the memory thing is long history. So you don't ever need to cycle or fully discharge the packs to prevent memory.

You should cycle once in a while to make sure the packs still deliver full capacity. Not because of memory, just because they DO wear out, and sometimes you get a bad cell that just dies sooner than it should. (think about it, they make millions of cells, once in a while a bad one WILL come off the production line).

When you do discharge, you want to do it as you describe, with a quality discharger, at a reasonable rate. Dischargine a pack to 0 can be bad, because one cell might read 0 before the others, then get reversed as the stronger cells continue to discharge. This is really bad for the batteries. (discharging an individual cell to 0 won't hurt it. And a well matched pack of cells that all discharge exactly the same can be run down to 0, but as with any mass-produced item, the cells do vary a little in actual capacity, so the odds of getting 1 weaker cell in a pack, and haveing it reverse is non-zero).