has anyone tried wambam no dig fence
There is no set reason that you have to use cement to set the posts into the holes. In many instances it can be effective to simply dig the post holes, set the post into position and then dribble the dirt back into the hole and tamp it in with a length of 2x2 or 2x4 to pack the soil in place around the post. 

In my farming days past we built lots of fences this way. It does not work well initially if the soil is too wet or too fine grained sand.