BT are just catching up to the way we have been doing things in NZ for several years
Until now, BT have stuck doggedly to the 3-wire system for wiring phone circuits around a house. The third wire is a bell-ringer signal that was originally used on the first electronic phones which hit the market. For many years now, this signal has not been used by phones which are all 2-wire these days.
However, the 3rd wire can be a source of problems for ADSL as it couples interference into the line. This can happen in the case of faulty appliances (as mentioned in the article), or if you live nearby to powerful AM radio transmitters on the Medium Wave broadcast band.
Therefore, it's best to ditch the 3rd wire completely which is what we have done in NZ with our 2-wire system which was introduced at least 6 or 7 years ago IIRC. If your house is newer than that, then it should have been wired according to the 2-wire standard.
The gadget referred to in the article, by the sounds of it simply disconnects the 3rd wire at the Master Socket.
So; to answer the original question:
Would this gizmo work in NZ?
- If your house is already 2-wire (as shown by a 2 stamped into the front of your various phone outlets) then it won't make any difference
- If your house has a 3-wire system, it could possibly work
- If your house is so old that it predates the 3-wire system, then most probably the gizmo won't make any difference