A way to enforce Safe Search for Google, Bing, DuckDuckGo, YouTube, and Pixabay w/o editing dnsmasq config files.
Add the custom.list file in this repo to /etc/pihole/ as custom.list by running the follow line.
sudo wget https://raw.githubusercontent.com/mwoolweaver/custom.list/master/custom.list /etc/pihole/custom.list
then restart the pihole-FTL service for the changes to be active.
sudo service pihole-FTL restart
you might also have to flush the dns cache on the devices using Pi-hole.
I noticed pi-hole/pi-hole/pull/2978 and have been wanting to use SafeSearch
https://discourse.pi-hole.net/t/import-etc-pihole-custom-list-for-easier-safe-search-enforcement/