they are a lot more careful when they have open fire in their lanterns, believe me...
Our children's kindergarten used real candles (Montessori, what do you expect?), and everybody, including the biggest ruffians and can't-sit-stills, held their lanterns very carefully, almost with reverence. In the 6 years we had children there, not one lantern went up in flames during the procession.
Come primary school and mini-bulbs on plastic sticks, and the first lanterns were already lost to lantern-fights during assembly, before the procession even got going. More amateur lantern fencing and backstabbing to follow during the actual procession, obviously, and by the end, about 20% of the lanterns were out of commission.
So, if you want to keep the lanterns, candles are definitely the way to go - but if I remember your original post correctly, you were actually looking for ways of disappearing them - then a Leuchtstab would be your weapon of choice.