"Breathing" holes bored through each charcoal briquette would greatly increase the oxygenated air flowing through the charcoal as well as the exposed surface area for burning.  Fire would catch and spread more quickly and each briquette would burn and "whiten" more evenly.  Each bag would weigh less because of the charcoal missing from the holes, also resulting in less material use and production cost.  

A briquette could either have one hole in the center [o]
or four or five small holes [::],
whichever proves more efficient.