During the last Gulf War we used Burn out latrines like that, what happens is that on a regular basis the latrine has diesel fuel added and then is set on fire, Hence the prase "SH*T Detail"..... after the burn is compleat you add just a little fuel to the bottom of the can to insure compleat combustion on the next burn.
This is of note becuse of a DAP didnt have any diesel and substituted Gasoline...... and the next user ignored the no smoking sign, Blew the hole shebang into flinders, and put a splinter 8 inches long and as big around as your thumb through his butt cheek.....He tried for a medal based on it being Enemy sabotage..... and we laughed him out of camp.
Gunns