I have been in that situation in a startup. The boss would come to me and ask for some dark pattern (not cookies, I don't remember exactly what it was). I said I wouldn't do it. They literally asked a guy in the adjacent room, and he took it as a new task and did it.

He was not a bad guy: I did not care about getting fired (I was young and single), he did (he had a family). And in his opinion, if the boss wanted it, anyway it would end up being done. His job was to implement what the boss wanted, not to contradict the boss.