How do I clear the unused conflict files down after resolving conflict?

I have resolved a conflict using p4Merge. It worked and the file now has the updated text. However in the folder is a load of junk like...

• --> file.txt.BACKUP
• --> file.txt.BASE
• --> file.txt.LOCAL

How do I made sure my merge tool cleans up these files afterwards?

git clean should do the trick.

git clean -f

That will remove to remove all untracked files in your repository, so be wary of inadvertently deleting other files. If the merge backups are your only untracked files, go to town. :)