Figured something out using CRON jobs. Here’s how I did it for those who want the same setup 🙂

1. in your functions.php –

/* CONTACT FORM DUPLICATE ENTRIES CRON JOB */
function delete_all_duplicate_killer_data() {
    global $wpdb;
    $dkdb = apply_filters('duplicate_killer_database', $wpdb);
    $table_name = $dkdb->prefix . 'dk_forms_duplicate';

    // Delete all records from the database table
    $dkdb->query("TRUNCATE TABLE $table_name");
}

// Hook the function to a custom action hook
add_action('delete_all_duplicate_killer_data_hook', 'delete_all_duplicate_killer_data');

2. Install “WP Crontrol” and then add new Cron event with the following values –
Hook name: delete_all_duplicate_killer_data_hook
arguments: leave blank
Next run: up to you. But I did “At this time:” with 12am and “Once Daily” recurrence.