I ordered potassium nitrate off of Amazon last night. From what I read, I can fill the cracks with that then add hot water to dissolve and soak into the wood. Then light it up. I like the idea of adding the charcoal as well. I really don't want to cut it. There are areas where rock is in it and areas without rock. It is a mess. I read that oak roots are 18 inches below surface. It does seem like they go deeper than that though. I think the issue here is that they weave in and out of the ledge.
Any experience with the Potassium Nitrate?