Pipe cutting advice

Please someone help a newbie . I’m fitting a magnaclean and the Pipes are too close to the walk to use a pipe slice . Obv I can cut it with a hacksaw etc but will the copper filings cause issues running round the system ? Or what’s the easiest way to flush them out ? I guess I could chip the plaster away from behind the pipes at worst.
Many thanks

 

Copper fillings can cause serious corrosion in steel radiators...pin holes etc.
Knock a lump out of the wall and use pipe grips to turn the pipeslice.

 

Yeah that’s what I thought and obv want to avoid ! May I ask your view on where to install the magna clean ? I know it goes on the return to boiler but instructions say before the filling loop . Some have said it doesn’t matter ?
Cheers