Greatly improve the performance of a WooCommerce site bogged down by tens of thousands of historic orders. Back orders up using your favorite Order Exports plugin, or rely upon integrated accounting software to keep history beyond the currently active orders in processing.
If you empty the WP Admin > WooCommerce > Orders > Trash with hundreds of orders inside, you may receive a timeout error of one form or another. Usually the trash will continue to clear. If not, simply return to the Trash later to clear out the remaining orders.