Add this alias (enter this once on your terminal)
git config --global alias.cb '!git fetch -p && for branch in $(git for-each-ref --format '\''%(refname) %(upstream:track)'\'' refs/heads | awk '\''$2 == "[gone]" {sub("refs/heads/", "", $1); print $1}'\''); do git branch -D $branch; done'
so whenever you need to clean your local branches without removing just need to