It depends on your "dodgy" data. Why is your data 'dodgy'?
One option is to drop the keys on the target, insert all data and recreate the keys. Perhaps a better approach is to analyse all foreign keys, so you can insert all data in the proper sequence. This last approach will have an instant check on the relationships when inserting data.
** Don't mistake the ‘stupidity of the crowd’ for the ‘wisdom of the group’! **