And personally if I return stock to a supplier I will use Inventory Adjust and "Shortage". This way I can easily track later via Shortage Reports what was taken out, plus it gives me my cost on the product so I know if I shortaged 20 items at a cost of $200 that I better see a credit of $200. I also can easily print 2 shortage reports afterwards, one for my records and one to send back as a Packing Slip to my vendor.
Not sure which way is better for you but that works great for me