Hello Chris,
Maybe you could do a little better.
The idea is that the 'in' and 'out' of the cable in the ring should be as far away from each other as possible.
I don't remember where I saw the drawing, with such a big ring.
I use that idea with smaller rings, but it's not the same cute design, and a picture would be of no help. Just finding a way to wind the cable in the ring so that the 'in' is never close to the 'out'.
Apart of that, for a mains AC cable, you can use a so-called 'lightning protector' *with an EMI-RFI filter*. Don't care too much of how many dB's are announced, as there are several ways to give a figure. They are useful from 100 kHz to 100 MHz approx. (not quite good at those limits), and the best filtering is around 10 MHz quite approximately. Once more, the 'out' should not run back near the 'in'.
Ray