Also for Android devices I find Rethink in DNS only mode with locally downloaded block lists works pretty well and is pretty private. Only issue is it takes your VPN slot, though it itself can connect to a WireGuard VPN as well, but if you need to enable and disable VPNs for various circumstances or need other types of VPNs that require nonstandard protocols or software to connect to then it becomes a pain. But this when when you leave your network DNS behind, you still have some protection and it's all done locally.

Best practice is to host 2 PiHole instances, if 1 DNS sinkhole fails you can fallback to another one (Primary & Secondary DNS Server) that way you don’t lose internet access.

Certainly read and try to interpret the documents as best as you can, I suggest going the Docker Compose route for hosting as it’s quite straight forward and a great tool to learn if you want to selfhost other software, fiddle around with 1 DNS sinkhole before you jump head first into getting the second one up though.

FYI it works on anything. I hosted it on a Raspberry Pi 1B (the very first one, it’s slow shite), and now I host it on an Orange Pi Zero. It’s not as slow, but it’s not too powerful either. Both devices are plenty for this project.

Recently, someone hosted it on a ESP32 or something. Not giving the link, simply because I don’t know which one is the genuine one. I use the project for close to a decade and it’s just works, mostly.