I hate the phrase "Dead Cat" but I don't have a love of cats (these poor misinformed animals seem to like me) either, they make good preventative devices......
My wife made one from fake fur she bought at a local sewing shop. Less than
$3 and ten minutes she had one sewn for me. Slips right over the
on camera mic.
As jrazz pointed out you can help but I never was able to get it removed in post.