"In the olden days Chaharshanbeh-Suri was celebrated in a very different way. It was originally a Zoroastrian tradition held on the last Tuesday evening of each year. Each family would light seven bonfires on the roof of their house and jump over them. After putting out the fires, they would pour the ashes over the rooftop along with salt and some coins to rid themselves of bad luck," Pishvaii added
http://www.mehrnews.ir/en/NewsDetail.aspx?NewsID=651698
Well this guy is not really allowed to go into it in much detail. In fact it is the most popular of festivals. Nowadays the Seyyeds have gotten so jealous of the event, that they ban it. I am pretty surprised that they have allowed it on this occasion. All over Iran fire crackers will go off inside people's gardens. And nowadays the opposition parties use it to whip up bravery against the Seyyeds. And that really annoys the Seyyeds.
The process of cleaning ones aura is very old in human cultures. We all love lighting a candle, and sitting around the fire. Well Iranians believe that the fire will burn all the yellow weak and bad thoughts from your spirit. So they jump over the fire demanding the cleanliness, stating words to that effect. We say, "Zardieh man az to, sorkhieh to az man", which means, I give you my yellowness (fear) and you give me your red heat or strength.
This ritual has been criticized by younger religions. But we all know the psychological benefits of the light of the fire. We Iranians are not Fire Worshippers but we respect the Fire as most powerful of all. In our traditions Qumars invented the Fire to allow Homo Sapiens Sapiens survive and move up the food chain. Archaeologists have found one of the oldest sites in the world in Kashafrud where the Orduwan period exists. This links with the myths in the Zend Avesta. There are temples in Iran where the Fire has been alight for 7000 years by carefully selected sandal wood.
All of this purification is part of the preparations before the beginning of Spring at Equinox. At that point all Iranians are ready to wear their new clothes and start the new year cleanly with the Rite of Spring. And the festivals are much more popular than anything anyone has ever tried to enforce on us. The turnouts are immense. I hope that the world press reports their popularity compared to anything the Seyyeds want the people Iran to do for them to stay in power.