This is certainly not for the weak. Walking dips is one of the hardest things I've ever done. Put a weight vest on and the "hard" just became "impossible".
Set up two bars on the safety pins in the power rack. Place them about shoulder width apart. Make sure you put them high enough so you have to perform a slight dip in order to pull yourself up.
Once you push yourself up, begin walking your hands from one end to the other.
Your chest, shoulders and triceps will hate you.