If its the pot I saw on your blog, then here's some info I dug up....It looks similar to raku/pit firing.
hope this helps!
The Traditional Firing Process - Bark, Dung and Manure
A thin coat of grease is then applied by hand to increase the luster and reduce the drying shrinkage. If the pot is to have designs they are applied now with the slip solution and the pot is ready for firing. However, the temperatures reached in the firing of pottery today are not high enough to make a pot waterproof.
The potter still builds his or her primitive kiln from corrugated tin, racks, tin cans, whatever she has found to be successful for her. Pots are placed between two sheets of tin, not touching each other, which are then covered with bark. After lighting the bark, the tin becomes red hot with the actual firing lasting about 30 minutes. The pottery must be allowed to cool slowly. In order to achieve the black pottery, cow dung is mixed with the bark and when the fire reaches its maximum temperature, it is smothered with fine horse manure. This sooty smoke penetrates the pores and turns the pottery black. From this lengthy process come beautiful original works of art.