Force Carbonation and Kombucha??

Hello,
I am trying to force carbonate my corni keg of kombucha. This is my first attempt at kegging and carbonating.
I am having issues with the actual force carbonation process. First thing i did was fill kegs and chill overnight. Next i hooked up my CO2 line and purged all the O2 out of the keg. Once that was done i laid the keg on its side (gas line down) and proceeded to force carbonate at 30psi while gently rocking the keg back and forth for 2 minutes. I came up with process after researching force carbonation and from all the videos this is one of two ways to force carbonate. Many of the videos i watched, once the the two minutes was up they were able to hook up the beer (kombucha) line and set the CO2 pressure to serving pressure (8-10psi) and serve carbonated kombucha.
Unfortunately, i was able to serve kombucha but none of it was carbonated.
What am i doing wrong?
I know the other way to force carbonate is to hook up the CO2 and leave overnight at a lower pressure (usually serving pressure) and 24 hours later you will have carbonated kombucha ready to serve.
Any help would be greatly appreciated.
Thank You
Cheers

It takes about 5-10 minutes of rolling back and forth to force carbonate a keg of beer. Gas line should be UP. You can hear the CO2 streaming in and the regulator groaning. The smaller the headspace volume the longer it takes.

With beer it's best to purge the headspace right after filling, not the next day or later, to prevent oxidation. Kombucha is not as O2 sensitive, but I'd still treat it as beer.

After the rolling is done, put the keg in cold storage for 24 hours. Reduce to dispensing pressure and tap. You can pull a pint or so before that, but beer will be very foamy. Now kombucha doesn't have any head retention proteins in it so you won't get a head, it's more like tapping soda. Chances are you'll need to carbonate and dispense Bucha at soda pressures, in the 50 psi range.

The "set and forget" method of carbonating is done at serving pressures and takes a week, sometimes two, way longer than a day.