This can be done in step 4, Amazon Mapping Wizard. If you have uploaded your products to Amazon already, removing a brand or Manufacturer in Amazon Mapping Step 4 will zero out the quantities of any product on Amazon that is in that Category or with that Manufacturer. You can also remove products that contains words or phrases there as well. Popular things that you can enter in are words like "Clearance" or "Sold Out". It is case sensitive.