Luckily havent haqd to deal with it in awhile, when ive had coworkers come out with stuff ive polietly either explained how theyre incorrect, ive also found using humour/jokes is a good way of getting people to see when theyre being incorrect

Unfortunately it seems to be rife now, a friends son recently did work for a MP and said when he was allowed to sit in on constituents coming in to see the MP about 80% of the time it was about immigrants, and the rest the usual stuff about roads etc