function git-clean-orig {
git status -su | grep -e"\.orig$" | cut -f2 -d" " | xargs rm -r
}
If you are a scaredy-cat :) you could leave the last part off just to list them (or leave off the -r if you want to approve each delete):
function git-show-orig {
git status -su | grep -e"\.orig$" | cut -f2 -d" "
}