Certainly you remember the paper Rammed earth constructions: Trans-cultural research in the Sonoran Desert by Mary Hardin. You know, the one that said:
"Formwork design and testing focused on the goals of easy mobility and reassembly. Early prototypes developed by Brittain and Perry used plywood walls stiffened with steel sections (later replaced by aluminum to lighten the forms' weight). Aluminum angles allowed the plywood pieces to bolt together easily and doubled as handles for moving the forms. However, the pressure built up during tamping made disassembling the forms very difficult. The sides bowed in spite of the stiffeners, the assembled forms were hard to move around, and they could not be stacked one upon the other."
Well, I found this website, also written by Mary Hardin. Do note the passage that reads:
"The materials for the rammed earth walls were very cost effective; they came from the reservation's resources of earth (sand, gravel, adobe, catcus ribs). The construction techniques also were designed to be cost effective utilizing simple forms that could be assembled and disassembled by two people and, and light weight tamping equipment. Note too that the cost of bringing conventional construction materials to the remote site would be very expensive."
Another gem from Professor Hardin!