I've tried this approach. Try to focus on a very narrow, easily provable set of facts. Anything that relies on media reports will not be sufficient. You need original quotes, preferably by Republican sources. The theory is that if I can get them to agree that something out of their echo chamber is false, maybe that will drive enough of a wedge that they will stop listening to the echo chamber. It's like the Miracle Worker, where if I can just teach them to sign W-A-T-E-R, everything else will fall in place. I haven't been successful yet. I've been able to convince them of a single item, but they quickly change the subject. They don't want to examine why they believed the bullshit in the first place. Still, I will continue to try this method on people who are at least trying to appear like they are engaging in a conversation.
I've done this approach, mostly on random social media. The idea is that if you get them to show their ass enough, they won't enjoy it, and maybe they will be more reluctant to post bullshit. It does nothing to help change their mind, but at least it can slow down the rate in which they post misinformation. I've had some success in this.
This is what I have discovered when challenging them on human rights issues. As long as they can pull out a "both sides" argument, there is no reason to address the basic problem. It's not important whether kids are in cages, causing trauma that will haunt them for the rest of their lives. The only thing that matters is whether the Obama administration also put kids in cages. Because the political point is more important than ending the cruelty. Because the cruelty does not bother them, it only bothers them that it might hurt Trump.