I shot a 2" PVC 20 feet and hit a foot wide hole in my garage floor.
Use a round plumbing cap. Make a drill head with one big hole in the center ~3/8" and 3 smaller holes ~3/16" near the edge. Glue an elbow and a couple feet of pipe on the far end and use it as a lever to twist the pipe while you push. The hose fitting goes on the end of the lever.
When you find the end, cut off all the plumbing parts and glue on your sweeps.
You will see the target hole filling with water when you get close.
