Hi,
If you "Receive and Invoice" when posting the PO, and nothing has been received already, then no accrual will be created regardless of whether the Item is inventory or non inventory.
For Inventory items if you just "Receive" when posting, and "Expected Costing" is switched on in Inventory Setup, then an accrual will be created. However if the item is setup as Non-Inventory then when just receiving the PO no GL entries are created. GL entries are only created when posting the invoice for non-Inventory items.
Therefore if you want automatic accrual postings I can only suggest setting up the item as an Inventory item.
See below for an example of posting a Non Inventory item on a PO:

Click Post and choose "Receive" and no GL entries are created:

Thanks
Gavin