Do Mormons really believe that magic undies,secret handshakes,secret names and chants will get them to heaven?

Uhh. Almost all religions have "silly" ritualistic and traditional things like this. In some sects of Christianity you eat crackers that are supposed to be Jesus. In some sects of Islam you dress up from head to toe in cloth. In some sects of Judaism you can't eat certain foods for no real reason other than the fact that you can't.