Thanks for stopping by Akira. Yes, having a special place to burn them makes so much more sense. In India, there is also custom of throwing idols in water bodies like lakes or rivers or oceans (which ends up polluting the waters, causes harm to water-life from the paints/chemicals from the idols). During large festivals, government designates a specific area in those waterbodies (sometimes creates an artificial ones) where everyone throws their idols and govt. immediately removes them from water to dispose them somewhere else.