There is an option to remove all stock for a customer, be aware this will remove all their stock through an adjustment Sale Order.  This adjustment Sale Order can then be removed if a mistake is made.

To find this setting first go select Contacts in the main menu, followed by Customers in the drop-down menu. go to Customers

Find the Customer that you wish to remove stock for and select them, then, on the view Customer page select Edit.

Once on the Edit Customer page, select the Warehouse Management tab, followed by the Storage sub-tab.

Use the red remove button as shown below.

If your customer has stock in multiple warehouses within your CartonCloud tenancy, the stock will only be removed from the warehouse that you are currently working in: