Remove Duplicate Artist Name

What action can I use to remove duplicate Artist from an id tag?
Expression
All duplicates are separated by "`` \`"
The topic from 12/2010 did not work for me.

Here are a few examples:
Pixie Lott\\Pixie Lott
Coldplay\\Coldplay

If you mean this thread:

You may notice that those artists had a forward slash and were not displayed with a backward slash like yours.

Try an action of the type "Remove duplicate fields" for ARTIST.