Disinformation has been an active area of research since the Cold War. Yes it is effective, though obviously there are limits. Maybe you can convince people that a celebrity did something even though it’s not true, but you can’t really convince a particular invididual that they themselves have a different name and history. Here’s a good survey of the state of the art circa 2022 (skip to “Findings of qualitative analysis” to see summaries of studies): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10446021/
Yeah, that’s the tough one. I saw your post, and I think it’s a great idea to ask for volunteers and suggesting that they post.