Short checking is your best bet, and he can easily justify such with the 24 hour layover. If I were you, I'd give him $50 for a hotel in exchange for the favor.

Eta: For the sake of clarity, your "rerouting" options are illegal. You need to check the bag in yourself at the CA counter.

1. Friend checks bag to pek
2. You meet him there to receive the bag
3. If he doesn't want to wait for you, luggage storage is an option