Any natural fiber rope will work. Nylon probably won't retain scent as well as cotton or hemp. Old anchor rope from salt water areas works. So does used barn rope and cotton horse leads. If you find scented rope, lay it in the bed of a pickup truck for a few months before use. I have both part one and part two of my articles on our website with some photos. Hang the end closer to three feet than four feet and make it easily visible and rigid if possible. Actually you can hinge cut a horizontal branch, bend it down and get by with a 12" piece of rope zip tied to the end of the hanging branch.