What I've found helpful in making these types of people question their bloodthirsty beliefs, or at least backtrack on them IRL, is to ask them what they would do if they were Ukrainians in Ukraine now, or if they had a home or loved ones there. Even the most rabid ones usually stop after hearing this, if anything because they see how deranged their stance is. I doubt it would make random libs online back down, since shame doesn’t play a big role in anonymous spaces, but still