It only worked in this case because those bots are run by twp different people. It is incredibly easy to prevent one's own bots from talking with themselves. The most practical solution I think is similar to what the Fediverse does, distributing different blocklists around. Though in Nostr's case, it would have to be very easy to update blocklists dynamically and let each user choose the ones they subscribe to. My only concern is the ease in auditing and forking the blocklists themselves. Otherwise the owner of a blocklist will just block anyone who criticizes the blocklist, and nobody who's subscribed will ever find out about the problems with it XD