I've driven a E150 van that had a sticking torque converter. You could turn off the ignition and the van would die, if you turned it back to run while it was still moving it would start back up without using the starter. The pump is ran by the input shaft, but if the transmission is in gear with the torque converter locked up, the output shaft is coupled to the input shaft, coupled to the engine via the locked up torque converter. So, yes it could work, but only if the transmission had enough residual pressure to hold it in gear (you couldn't start from a dead stop). To start from a dead stop you would have to devise some sort of accumulator to apply pressure to the clutch packs. But, why would you want to push start it? The time and money spent on locking up the torque converter could be better invested in a new starter.