Kite Duelling ?

When I went to Brazil this past summer, you would see kites everywhere! But the ones they have there look and function significantly different from the ones I see here in the States. They would use this adhesive that had gl shards and put it on the string, and then duel each other. Whoever could cut the string of the other kite would 'win'. I bought a few but I don't know have to maneuver them as well. Does anyone know about how these kites got over to Brazil, and perhaps any tips on flying them properly? They're really unstable.