With no hydraulics no amount of force on the controls is going to make any difference. The controls are locked, so applying force to them before de-boosting is pointless. With three crew the flight engineer can deboost while the captain continues looking out the window. With two crew the captain has to bend to the right, reach down to the floor and simultaneously pull three cables, then hope that when he looks up his windscreen isn't full of terra firma. Personally, I think it's crazy. I was on an Electra where we lost all hydraulics just after take-off (Bus A failure during gear retraction), and if we hadn't had a flight engineer I do not think I would be writing this now.