Non-billable time entries will be cleared out once you have completed your Billing procedures by printing and purging the Billing posting journal. No, the detail of this time does not show up anywhere else now, except the Time Utilization report.

You are correct - there is no way to "final bill" to clear out the non-billable time. Since it is "non-billable" the above procedures will suffice.

Hope this helps.
Regards!