Here’s my take on the subject:
The square-link plant ties are Chainlock.
The following recipe requires duct tape, the handyman’s secret weapon.
I provide here a snapshot of my home-made post driver:
It consists of a two-foot length of 2" galvanized pipe for heft. Threads on one end must be in good condition to accept a cast cap as a hammer. To use, slip the open end over the conduit. Set the conduit upright, lift the driver, and hammer the conduit into the ground, using the pipe as a guide. It takes some effort even in sand. You may need a ladder for this. I do.
Use duct tape to mark the four-foot point on the conduit before driving it in the ground.