Expense Subinventory Items/Expense Items Get Costed When Used in Work Order Material Requirements

We are currently facing an issue on "Expense Items" or Non-Asset items issued to a Work Order/WIP Job.

We have defined several subinventories of items with SOH where Asset Inventory check box is NOT checked and included as special character * in the subinventory name for the purpose of setting the cost of these stocks under this subinventory to zero (0 cost).

However, when materials under these subinventories are issue out of store to Work ORders, it carries the average cost of the items under asset/non-expense subinventory.

Is there a solution or work around we could use such that when using these items against work orders, no cost will get involved?