Need a bullet proof workflow to sync up with an external audio

I shoot at 60p (59.94) but deploy to a timeline of (30p 29.97)

I own 2 tentacle units and am able to sync 2 video cameras with no issue BUT

I can never get my video to line up with an external audio source such as an h4n.

The audio of the external source is constantly drifting.

Please help me develop a workflow so that I don’t spend hours on this every project.  Tentacle was supposed to save me time but so far it hasn’t fulfilled it’s promise.

Thank you