Hmmm, send it back to R&D. The expelled gasses going directly into the horn would only produce a single-toned "HONK". Instead, those gasses could be used to inflate a cuff that's wrapped around a more traditional style clown horn bulb, squeezing the bulb and producing that same noise; but as the cuff loses pressure and bulb reinflates, the air it draws back will produce second tone, providing the clown horn's signature "HEE-HAW" that our prospective murder victims expect and deserve.
Yes but direct gas impingement on a rubber chicken is going to wear some parts. Better to have an indirect system and avoid carbon deposits in your comedy noisemakers.