DNS blockers became a thing in part because /etc/hosts can't do stuff like glob subdomain blocking, no?

e.g.

*.bla.tld 127.0.0.1

Re-invent the wheel - it’s always less hassle! I’m quite sure your script will be far better and more stable than setting up a dns server to do the blocking.

You can’t change their routers name server but it’s easy to install scripts on their devices?

Just put pihole or other dns server with blocklists somewhere on the internet (you can even host that at your own home!!) and point their routers upstream dns to it.

Just run Pi-Hole in a Docker container on your machine. Point your nameserver to localhost and reap the benefits.

Ublock Origin is not an option? It automatically updates blocklists, and can block ads served from the same domain as content, where hosts based blockers can't help.

Afaik dns based blockers like pihole are useful for locked down systems (iphones, smart tvs, consoles, not rooted android phones) where you don't have access to other ways of blocking ads.

I think Tblock should do what you're asking for.

maybe the scheduler cron in combination with git might work for you?

I know you already found something that fulfills your needs, but the mullvad doh servers can do blocking and then you’re doing dns over https with dnssec and a few blocklist options.

Run pihole on a server somewhere, accessible only via a vpn. Install the vpn on their devices.

I haven’t tried this but I recall someone saying it was how they had it setup.

You can use Tblock - Or you can check which router they have, and tell them to flash it with FreshTomato

Then their router can service as a raspi with a pihole: https://wiki.freshtomato.org/doku.php/advanced-adblock