Delete merged branches, both in origin and locally

gistfile1.txt

1. Delete the branches in my remote `origin`

git branch -r --merged | grep "\origin" | grep -v "\master" | cut -d"/" -f 2 | xargs -n  1 git push origin --delete

2. Delete the branches locally

git branch --merged master | grep -v "\master" | xargs -n 1 git branch -D

Would -d for the local delete be safer?