If it where me I would use the pallets, you can get some long pieces out of it. I would say burn three pallets as hot as you can get them. Let the fire cool, dump the ashes, rinse with water, use a wire wheel to clean it, then burn 3 more pallets through it, make sure you get a hot fire on the bottom of the barrel also, that is where your second burn will come in handy. When that is done, rinse it, wire wheel again until it is really clean and take it to the car wash, use some engine degreaser and wash the crap out of that thing. Then wire wheel again.......then wash it with some dish detergent and a scrub brush, rinse and your done....go and build the thing. If you want a good finish you will want to paint it ASAP or you will get rust starting to form fairly quickly. I never painted my drum and now kinda wished I had, but then again that is why they call it an UGLY drum smoker.