I use the lint wax egg carton cubes all the time as firestarters for my charcoal when I camp cook. They burn about 5 minute or so, with enough flame to get the charcoal in the chimney starter lit. They do need to be protected from the wind at the git go as AyersTG says. Adding tree pitch to the wax makes them unsuitable for the grill, but definitely adds to their combustability.