Curl Cord Detangler - It isn't quite as nice as the discontinued Sony TL-3F as shown on the right. But if you need some it does work with your help!
I may have been a little too negative on my initial evaluation on the below item. I felt that it was a poor substitute against the Sony. It did not rotate freely. Well, I went back to the one remaining Sony unit and tested it. The Sony detangler did not rotate simply from the pressure from a moderately tangled cord either!
The more commonly available detangler (one solid piece with the cord jack on the side) certainly rotates nicely. However, due to the normal angle that we hold the handset the cord cannot overcome gravity to rotate over the device to detangle the cord anyway. If the handset cord is allowed to sway the one piece construction really transmits that annoying noise. When I was using one of these on my own phone I would hold on to the detangler while I talked so that it wouldn't make noise.
So, here we are. We can only offer a detangler that you need to manually turn to make it work. It is quiet in use since it does not rotate while you are talking. The attached cord is fixed (cannot be replaced or made longer) and it varies from 1/2" to 3/4" between the barrel and the modular plug. It is only available in white. Recent shipments have a clear plastic cover exposing the inner workings. This detangler is physically smaller than the Sony and the price is right.
I saw that my cord was starting to get tangled. I just reached up and gave the detangler a couple of twists in the right direction. It wasn't too much effort and it took care of the problem.