When you enter an inventory product into the Inventory master file you must assign to it a general ledger sales account (income statement revenue account). If you have the C/Books Inventory Control System you must also assign to each product a general ledger controlling account (balance sheet asset account) and a general ledger cost of goods sold account.
When an invoice is entered, the customer account is debited and the sales account is credited for the price of the product. If you have the C/Books Inventory Control System, the controlling account is credited and the cost of goods sold account is debited for the cost of the product (the cost of the product is calculated automatically when you STORE <F5> the detail portion of the invoice).
When entering your set up product, enter the Accounts Receivable controlling account in the Sales Account field. If you have the C/Books Inventory Control System, it doesn't matter what you enter into the Controlling Account and Cost of Goods Sold Account fields because the cost of the clearing product is zero, so only a zero amount is posted to these two accounts.