Social media sites should have 'reverse' Parental Controls; where adult children can block their boomer/senior parents' accounts from viewing conspiracy and radicalizing content.
Solid password of what? The router admin panel? On the router that is physically in his home? He can just factory reset that router, and presto... Password is gone.
You'd have to cut off VPN, SSH, and proxies, too, and to stop a really slippery network person from getting around that, you'd have to inspect protocol, not just block ports.