yep, set your psi to 30, shake until the regulator isn't singing, and let settle overnight. in the morn, pull the pressure release valve, set the gas to your desired pressure and enjoy... i pulled from my belgian wit keg a little early... i wish i'd waited because 1/2 of the keg is gone and it's just starting to hit stride.
edit: this method risks overcarbing, i usually shake it for a fraction of the time, set it on 30 psi all night, release in the morning and set to serving pressure (12 psi) for a few days, then it's perfect.