Delete each branch that already in the branch master. Put it in you path and you will have auto complete functionality of git.

git-clean-branches

#!/bin/bash
while read -r line
do
	if [ "$line" != "origin/master" ] && [ "$line" != "origin/HEAD -> origin/master" ]
	then
		inMaster=$(git branch master --contains $line)
    	if [ "$inMaster" = "  master" ] || [ "$inMaster" = "* master" ]
    	then
    		branchName=${line#origin/}
    		echo "$inMaster"
    		echo "$branchName"
    		echo "$line"
    		git push origin :$branchName
    	fi
	fi

	#echo "$line"
done < <(git branch -r)