On 11/03/2018 09:25, ARW wrote:
Well it sort of worked

http://wiki.diyfaq.org.uk/index.php/File:CHcleaner.jpg

And for anyone who cannot see it's a magnetic cleaner so full of the
crud that it has collected that it has split open.

Slightly OT, but I thought it was possible use a Magnaclean (or similar)
to put inhibitor into a system?

I can't find any youtube videos of anyone doing this.