There’s no gaurentees Guru, which is why it’s probably an interesting project to build one. There have been articles on them in “Funk Amateur” and other radio magazines.
The principal of phasing signals from two aerials to remove QRM (note QRM, not QRN) has been around for many, many years.
Whether it will work in your specific case Guru, no one can say. By the way, I believe it’s not the LED lights themselves that cause the noise but rather the switched mode power supplies they run off. Have you tried running your gear off a battery in case the noise from your neighbour is actually coming up the mains leads - if so a Mains filter should stop that.