A couple of years ago I came across a fairly small specialist UK based company that offered some reasonably priced solutions for mains cleaning / isolation / filtration, iirc one of them included an external mains rod and some cabling.

For the life of me I now can't remember who they are / what they're called, despite hitting the search engines. It's that age-old problem of not being able to find the thing if you don't know what it's called! :-)

Does anyone have any suggestions?

Thanks,

Steve