[Koha] Deleting all records in Koha

I want to get rid of all the records in koha, not all the records had accession numbers when they were imported so the batch delete is not effective. Tried truncating the tables in MySql but when I search the OPAC, the records still appear as if nothing was done to remove them. Can anyone assist on how to truly delete all the records from koha? Regards, Davian Cooper