The message from Conrad Bladey 03 Mar 00 - 10:01 AM is the version I know - and the Besoms / buzzems debate is neither here nor there - simply people's ways of trying to write down the way in which Geordies speak.( For people outside of UK, Geordies are native to the city of Newcastle in Northern England and have and are proud of their very strong accent - somewhere between English and Scottish).
Anyway the version Conrad mentioned, lends itself to a good "sales pitch" for the Besoms - simple lines with a bit of human interest to get potential customers listening or hooked.
A bit further south from Newcastle near the Lake District comes a song about a young lady selling the same articles,called the " Lish Young-Buy- a-Broom ". Don't know for certain , but I always believed "lish" was a corruption of " delicious ".
Besom / besson / buzzem / bezom / broom take your choice, they are all modern day - brush - presumably from the same use as in brush fire.