The "yawning weapon", which was used during Banasura war, has to be one of the strangest weapons mentioned in scriptures.
Was it used on any other occasions?
Yes the yawning weapon used in Banasura war is used in other occasions as well.
First of all lets see what is the sanskrit name of yawning weapon it is called " jrumbhana , जृम्भण ".
This weapon is used in famous war between Vasistha and Vishwamitra for kamadhenu as mentioned in Valmiki Ramayana -Bala Kanda - Sarga 56 - Shloka 7
The brief story is Vishwamitra once visits hermitage of vasishta and there sees Kamadhenu - a wish fulfilling cow. He then asks Vasishta for her , but Vasishta denies that request humbly by saying that he needs her for purpose of Yajnas. Vishwamitra then tries to take her forcibly. But Vasishta by his power defeat all the army and kings of Vishwamitra .
Vishwamitra then Viswamitra fell into despondency and reaching to Himalayas performs austerities in order to please mahadeva . Mahadeva gives him supreme power (blessed with the invincible strength of the weapons) . Then Vishwamitra again attacks vasistha. Where he uses the yawning weapon against him We can read the full story from Sarga 52-56 of Valmiki ramayan.
मानवं मोहनं चैव गान्धर्वं स्वापनं तथा।
जृम्भणं मादनं चैव संतापनविलापने।।1.56.7।।maanavam mohanam caiva gaa.ndharvam svaapanam tathaa |
jR^i.mbhaNam madaanam caiva sa.ntaapana vilaapane || 1-56-7"Vishvamitra also launched missiles named Humane, Rager, Stupefier, Hypnotiser, Yawner, Intoxicator, also thus Humidifier, Weep-inducer.
So this yawning weapon is used by vishwamitra against Vasishta . in the shloka we can find all the names pf weapons used by Vishwamitra in that incident.