There was a customer we used to do that at when I was a new hire. The conductor would sit on the knuckle at the rearmost car and I'd stand on the steps of the locomotive. We'd bottle the air then start shoving. Right near the switch, the engineer would fully apply the locomotive brakes and I'd jump off at the switch while the loads of cement and the conductor would keep on going up the hill. The engines would then rapidly go the other way until they were in the clear. Meanwhile, I'd line the switch into the industry then get back out of the way just in case something went drastically wrong lol. When the cars ran out of momentum going up the hill, they'd come back past me and into the industry track. When the conductor saw me, he'd kick open the angle **** with his foot and the cars would go into emergency. I'd run over to line the switch for the engines which were on their way back towards me on the mainline. We never had any issues doing it that way, but you'd get fired about 7 or 8 times simultaneously doing it that way now lol