All are good suggestions...
D4man knows his stuff with batteries. I'm sure his discharge device works great. Here's some input from me as to what I use for my nimh packs since I'm one of the last guys still running them at my track.
Say I just finish a heat. I put the battery away for the day just as I take it out of the car.
When I come back the next race day, the first thing I do is discharge the entire pack down to 5.4 using my Orion Advantage charger.
I've had the battery discussion with many people and most seem to think a discharge tray isn't necessary for 1/10 scale offroad. It's mostly for on-road I'm told. I have one and use it periodically. I've noticed when I'm down on run-time on old packs if I cycle them and put them in my Tekin Battery Doctor they tend to come back with better runtime. If you're utilizing this, after you discharge the battery on the charger, you would then put the pack in this tray until all the lights go out. Then let the battery cool if it's warm, and recharge the battery at about 5 amps.
Hope all this helps. You can substitute the light bulb strands shown above for the charger if need be.