I have, but I have horses so I had a supply of fresh manure. I built it in the greenhouse in February piling it up until there was a heap squared off and flat on top, about 3' tall. I made a wooden frame from planks about 2'6" wide and 1'6" deep which I placed on the heap and half filled with compost. I made a lid to sit on it covered with clear polythene sheeting. It got quite hot and when the compost felt warm I sowed my seeds, tomatoes, annuals in it. It worked quite well but it took up a lot of room and was a bit in the way when I'd potted on the seedlings and needed the space. It sank quite a bit as it rotted down. Afterwards I watered it from time to time then spread it over the greenhouse bed to grow the tomatoes in the following year.