1 Brazil's answer to the vuvuzela was invented by Brazilian composer and Oscar-nominee Carlinhos Brown. Unlike the vuvuzela, it does not sound like a swarm of murderous bees.
2 "Caxirola" is pronounced, near enough, "cashy rolla". Think of Donald Trump rolling down a hillside. Not just to remember how to pronounce "caxirola", but for general merriment.
3 The caxirola had a disastrous debut. Some were given to fans at a Brazilian national game, and when Brazil started to lose they collectively decided to chuck their caxirolas on to the field. Which would have been bad enough even if the caxirola wasn't beautifully aerodynamic, allowing it to be lobbed over great distances. There were so many caxirolas on the field, they had to suspend the game. The players, to their credit, helped pick them all up.
4 Whereas the vuvuzela has cultural and historical significance in South Africa, the caxirola was invented specifically for the World Cup, with the brief that it should be less annoying than the vuvuzela, and quieter (which isn't hard given that the vuvuzela produced 127 decibels, not much quieter than a gunshot).
5 A single caxirola sounds like a rain stick. A mass of them sounds like a hiss. Thousands of them rattling at once sounds like the stadium is full of livid snakes.
6 The hope was that fans would shake the caxirolas to the rhythm of the beats from the Brazilian drummers at the matches. Because everyone knows if there's one thing you can expect from excited, possibly drunk, football fans, it's an exacting sense of rhythm.
7 Federal officials in Brazil have now banned caxirolas from all 12 of the Brazilian football grounds where the World Cup matches will be played – for "safety reasons". Perhaps because their grenade-like shape would allow real grenades to be smuggled in unnoticed. For some reason, the ban doesn't seem to have dampened sales.