I've been a egg owner for a couple of months now and love it. The only thing I don't love is spending a ton of money on charcoal. I have tried other brands and the only one that I love is the BGE brand which is $30 per bag. I usually fill my firebox up about 3/4 full but it doesn't matter what I cook and how long, most of the charcoal is turned to ash. I've heard stories that you should be able to cook 2 more times on the same amount of charcoal. Is this true and what am I doing wrong?