Thank you for getting back, @useraccounts5.
Yes, it is okay to use non-stock or stock items to track the products, then adjust the stock count through a journal entry if you didn't track COGS for your inventories. If you did, you need to manually adjust the inventory by reducing the materials used and increasing the finished product.
For additional guides while managing your products/services, feel free to open these articles:
I'm always here to help if you have any other questions. Just add a comment below. Have a good day!