When tracking inventory using COGS (Cost of Goods Sold) that is always what you might call "accrual" method. I think you're reading to much into it.
The cost that you paid for the inventory you sold are not deductible until the tax year you actually sell the inventory. It doesn't matter in what tax year that inventory was purchased either. So for income/expense accounting you are either using the cash method or the accrual method. There is no "hybrid" to speak of in your case, as regardless of the accounting method you use, it does not change how you account for inventory.
When it comes to inventory, you "are" using the accrual method regardless of how you account for any of the other stuff.
