Steve,
What gubbs3 says is pretty much true, but rebuilding the shocks that often might be a little overkill. I have two Nitro Rushes, one is for off-road and the other is strickly on-road use only. Changing the oil in the shocks is a good idea, but I feel that a rebuild is only waranted when the shocks are starting to leak. Depending on how often the truck is run and the action of the shock, is a good indication as to when the oil and a rebuild is necessary. As I had mentioned before, I rebuild when they start to leak and change the oil when the "action" doesn't seem to be just right. After each session, I go over each screw, bolt and nut to ensure they are tight. I clean the vehicle by blowing-off the heavy stuff with an air-hose (35-45 psi) then lightly spraying it with a 50/50 mixture of denatured alcohol and water then making with the air-hose again until everything is dry. Make sure you do this outside and wear some sort of eye protection. That is what I do. I hope it helped.