expiry best practice

we have been archiving for about 2 years along with a large pst ingestion.  we finally have an agreed upon retention.  based on the expiry report we will be deleting approx 24 million items.  we have been advised to step down the retention period until we get to our desired state.  since there will be a large data removal should any steps be taken at the database level in between expiry executions?

thanks