I particularly like the one where you clamp the pickup in your teeth and play through yer nose! The only drawbacks I forsee might be:

Tounging could be a bit of a bear. Dunno 'bout you, but I ain't got one in there.
Drool can be enough of an issue in the fipple; snot could really compromise one's intonation!
Aside from the aerodynamic influence of snot/mucous/phegm etc., isn't all that stuff nearly as conductive as it is gross? I'd think you might do well to stand on a rubber mat while performing / recording - plastic bag nonwithstanding - just to be on the safe side.

When recording with my fife (which our Tech was hitherto unfamiliar with) he put the mic way over in one corner of the sound booth and backed me into the opposite corner. I still heard muted sounds of distress from the master control panel when I let her rip in the high register (they do call it a "Battlefield instrument" for good reason).. but it came out all right in the end.

Do be careful, now; good whistlers are hard to find!