Both words don't actually exist. In this kind of case native Koreans just take the nuance of the word (kind of like jabberwocky..) but I guess it's kindda impossible for non-native speakers. FYI, 꽁기꽁기 was coined by a cartoon drawer and was introduced by his cartoon. In the cartoon the point of the word was that nobody actually knew what that meant. Ever since, term 꽁기꽁기 has been used to describe something as very undiagnosable or weird or vague etc... The term is only spoken/ known by minority(usually young juveniles who surf the net a lot.) 샤르샤르, I've never heard of before.