using bind to block domains

Is this bind usage a good way to block domains on a local network ?

root@gwen:/etc/bind# tail -2 named.conf.local
zone "facebook.com" { type master; file "/etc/bind/db.block"; };
zone "twitter.com" { type master; file "/etc/bind/db.block"; };

root@gwen:/etc/bind# cat db.block
$TTL 24h
@       IN SOA ns1.antwerp.local. paul.cobbaut.gmail.com. (
                  2012082800  86400  300  604800  3600 )
@       IN      NS   ns1.antwerp.local.
@       IN      A    127.0.0.1
*       IN      A    127.0.0.1

Or is there an obvious better solution ?