There is no way how to replicate this study. Its not clear what is core of problem. Are models poisoned? Is there problem with search. Sorry but there is no science behind this.
'This tactic is described as the deliberate deception of datasets that AI models — such as ChatGPT, Claude, Gemini, Grok 3, Perplexity and others — train on by flooding them with disinformation.'
By that I mean creating tons of spam content in places that LLMs learn from but that humans ignore.