Moderator + Beta Tester
DNS only blocks domains (like a HOSTS file does), it can't and doesn't apply cosmetic filtering rules.
;; AUTHORITY SECTION: $ dig @127.0.0.1 doubleclick.net doubleclick.net. 3600 IN SOA fake-for-negative-caching.adguard.com. hostmaster.doubleclick.net.
doubleclick.net A Empty
example.org 127.0.0.1 - AdGuard DNS will now return 127.0.0.1 address for the example.org domain (but not its subdomains).
I figured it out.I don't use OpenWrt, so I'd be the wrong person for such a tutorial I'm afraid. But if OpenWrt already supports DNSCrypt, just use the AdGuard DNS IPs as the DNS resolver addresses.