Excellent and intriguing research Robyn. I thought I'd got this one sorted but as you point out so aptly there can be many and varied theories on this subject. I Guess this is what makes this custom so special and unique. I for one are more than greatful to be able to play a small part (if only in a supportive role) in such a tremendous living tradition .
Any more information greatfully recieved.

OSS! OSS!
WI-HEE OSS!