Felice Pantone, aka Ugo when on stage, italian musician and member of the duet Ugo e Casimiro, has designed and commercialized a device called Reggi-Flauto (the "Flute-Clip"), specifically on the purpose of holding a nose flute without the hands.
Here is the original presentation video :
I have ordered some Reggi-Flauti from Felice Pantone and received them quite quickly. The flute-clip is quite simple, but efficient : it is made of a very strong plastified wire, ended by a metal clamp which holds a wire, strong too, but thin enough not to mask the flute, nor making the playing uneasy. This wire is the axis of a little foam-rubber pad which has a sticking surface on one side. This pad is to be stuck on the front of nose flute, yet allowing it to rotate on the axis for an easy positioning under your nose.