Having excess stock that is slow-moving is not a good idea, but few want to liquidate it with massive losses. The problem is they are left, its value will drop, and it ties up cash.
Here is a tip that may work better.
Try and make their purchase of these stock items a reward in your VIP club. A simple but effective strategy is double or triple points for purchases of these stock. It may help you get rid of these items without the need for significant discounts, and since these customers earn loyalty dollars, they will be encouraged to come back and buy more.