As many know BPL was a hot topic with hams here in the states.
I've often wondered why someone experiencing interference couldn't just hang a low pass filter somewhere, such as across their incoming, or even in the house plugged into an indoor receptacle. Take the BPL and it's noise to ground.
The problem might not be mitigated by putting a low pass filter in the house.
At HF, many of the fundamental frquencies PLT/BPL uses are HF frequencies to start with.
Whole swaths of HF frequencies like 2MHz to 5MHz or sometimes the whole HF spectrum from 2MHz to 30MHz or even higher. Any filter that filters out the interfering BPL would also filter out the frquencies you are trying to listen to.
Any filter on the power outlet in the house would not work, because power lines are not insulated (shielded) like coax. Power lines are usually just uncoated copper or aluminum wire strung between poles.
Because I live in the sticks, I don't get much PL or other interference.
Until last year, when I was plagued with a huge amount of broadband hash for virtually the whole spread of HF.
The culprits were a dodgy LED dimmer, a dodgy LED lamp and the really broad hash was coming from my LAN.
I binned the dimmer and LED, and put ferrite rings around every end of the LAN cables - about 9 turns each end.
The noise went from a steady S7 down to S1 and lower. There's still the odd splash and warble here and there, but I can live with it. Most recently, a cheapo PSU started playing up and I was able to quickly isolate that as the cause - while it lasted, it was fierce.
If I was still living in a town, I'd be driven to drink by neighbours' noisy appliances, I think.