How to silence ActionController::UnknownHttpMethod errors?

Since these are requests that you are not going to handle anyway, better way is to limit https methods at nginx level, so that these will not hit rails at all:

server {
  # (your vhost for this app)

  if ($request_method !~ ^(GET|HEAD|PUT|POST|DELETE|OPTIONS|PATCH)$ ){
    return 405;
  }
}