Informix permissions (IDS 9.30)

While reorganizing data in the database, we apply individual user permissions per person, per table to provide database security. The issue we have is anytime we drop and re-create the database, we have to apply all of the grants, in a recent restore it took 36 hours to apply the grants for 933 users to 899 tables (6 statements X 899 tables X 933 users). Is there a quicker way to apply the grants using onconfig parameters for tuning? Currently we open permissions up to public until the grants have been applied, then remove public. system parameters AIX 5.1 IDS 9.30/tools 7.30UC7 on a 4 way 8 gig IBM 690