Here’s a gelatin fining process. Using this method I don’t introduce [much] air into the keg.
1. Cold crash beer to induce chill haze
2. Use 1 tsp gelatin in 2/3 cup of water.
3. Let stand 15 min or so
4. Put it in the microwave for 15 sec.
5. Continue the 15 sec bursts until ~150*F (usually 4 bursts). This dissolved the gelatin and drives off most of the air from the water.
6. Pour the mixture into a clean, sanitized 2L plastic bottle.
7. Squeeze the air out and put on a carbonator cap.
8. Pressurize the bottle with a bit of CO2 until it pops back into shape (very short bursts required).
9. PULL THE KEG PRV to depressurize the keg!
10. Place a clean, sanitized jumper with a QD on each end on the bottle. Depress the QD plugger to force air from the jumper line and fill it with gelatin/water mixture.
11. Invert the bottle
12. Connect the jumper to the gas in post
13. Allow nearly all the liquid to drain into the keg
14. Quickly disconnect it before it all empties into the keg (you don’t want the air/CO2 mix allowed into the keg).