If you've memorized all the layouts, you don't need any kind of clue, so you don't need a kind of clue that's banned. You could for example clue "Sausage" every time and your team would play as well as the bot in the article. To play better than the bot, you might want to clue about words for 1 turn or so.
I would say that’s still against the rules since “sausage” has no relevance to the meaning of the target words. Obviously you could just bullshit some extremely tentative relationship if pressed but it goes against the spirit of the rules.
I feel like saying "<death card hint> 0" every time is 100% in the spirit of the clue-ing rules, and there's no rules related to guessing, so this guessing strategy also doesn't seem to violate things that overtly.
I do agree that there's an implicit intention in the rules that the operative's guesses are related to the spymaster's hints, but I don't think that relation is ever said explicitly.
But saying zero disallows your team from guessing at all, right? Maybe "<death card hint> 666" would work.
A common pattern in our play groups is when the other team is just 1 away from winning and you cannot find a clue that covers all your remaining words, you come up with the best clue you can and say "99" so that it's clear "The number is irrelevant to the clue here, just keep guessing until you win or you miss."
Edit: I'm wrong. From the rules: "If 0 is the number, the usual limit on guesses does not apply. Field operatives can guess as many words as they want. They still must guess at least one word."
Edit2: And instead of 99, my play groups should have been using "unlimited." Again from the rules: "Sometimes you may have multiple unguessed words related to clues from the previous rounds. If you want your team to guess more
than one of them, you may say unlimited instead of a number. For example feathers: unlimited."
Clues must be related to the semantic meaning of the cards, so irrelevant clues are technically banned. So, a "sausage" strategy would be illegal on many boards.
