Re: Fastest non-mechanical means of destroying stumps
Take a chain saw and plunge-cut some deep slots in the stumps. Then put a big bag of instant-light charcoal on the top and light it. Add more charcoal as or if needed depending on the brand of tree. Some are much wetter than others. The stump will be gone right quick if you get a good hot fire going. Pull up a lawn chair, a cooler full of your favorite beverage, and get out the marshmallow and hot dog sticks and have a bbq.
I once found some potassium-based stuff at a garden supply store that used this same principle. Charcoal works just fine, though. I've also used charcoal to dispose of dug-up stumps as well.
Oh yea, it will burn for a couple of days, so be sure you are comfortable leaving it go and the surrounding area is not liable to light off itself.
'04 Husqvarna GTH2548