Yes, filling your freezer with water jugs will reduce cycling. However, when it does cycle it will just turn on for longer. So, you really won't save much if any power.
I would suggest is checking the seals, cleaning and defrosting it, and turning the temperature up as much as you are comfortable with. When I had a chest freezer, I turned it up all the way and it was still below 0F. I keep my fridge freezer at 5F.
Defrosting my chest freezer resulted in a 5% reduction in energy consumption (it was pretty bad admittedly).
Turning the temperature up resulsted in another 8% reduction in energy consumption.