blocklist aggregator: https://github.com/jakeogh/dnsgate

just buy a pair of scissors

I wonder what happens when redirecting to 0.0.0.0 instead of localhost

It is the same. Except on Windows 8.1.

http://winhelp2002.mvps.org/hosts.htm

OP's tweet is about the iOS app.

then apply it to a router?

It only works if the router is also the DNS resolver, and if the resolver uses /etc/hosts as a source.