Cloud Nuke was created for situations when you might have an account you use for testing and need to clean up leftover resources so you're not charged for them. Also great for cleaning out accounts with redundant resources. Also great for removing unnecessary defaults like default VPCs and permissive ingress/egress rules in default security groups.
brew install skyzyx/cloud-nuke/cloud-nuke
Or brew tap skyzyx/cloud-nuke and then brew install cloud-nuke.
Or install via URL (which will not receive updates):
brew install https://raw.githubusercontent.com/skyzyx/homebrew-cloud-nuke/master/Formula/cloud-nuke.rbbrew help, man brew or check Homebrew's documentation.