I've used the nut and I think i had more waste with it - took almost 2 bags a day - now i can use a bag or less of rice coal - I may decide to buy some nut coal to add to my fire just before bed or before leaving since they're bigger chunks and might burn longer. But so far, so good.
since I cleaned out the stove and started new, I've been able to keep it stoking a steady 82 degs - after about 7 hrs it drops to about 76 and it's usually around the time I am ready to leave the house or go to bed so I will top it off. Because I got a good burn going again, the new coals take very quickly and strongly. It seems that the problem wasn't so much the wrong coal, but not cleaning the clogged uncooked coals from a weaker fire previously to the cleaning.
When the stove burns hot and efficiently, the ashes fall through the grate better and I am able to keep a good burn going longer. So, it was an unexpected surprise that rice coal does work. It's easier to manipulate and scoop, too. I use a KIRK brand 1 and 2 quart pot, scoop the coals, and my hands are protected when I dump them into the fire. I'm slowly relearning the art of coal burning, and learning new things by accident