Suggestions regarding how to loosen impacted sand and gravel in 4" PVC

[Captain Dirty]

Thought about using one of the sewer augers. Have a short one that's probably 6' or so. May try it.
Ralph

Inexpensive auger. Slightly different application: roots, dust, and asphalt shingle debris in a 4" clay tile between gutter downspout and dry well. I bought a "pigtail" (corkscrew) tethering stake from a local discount store ($2.00), welded the "eye" closed to give it some strength, turned it in first by hand then with a notched piece of 1-1/2" pipe, and pulled it out with a doubled nylon rope. YMMV.