Labor Clearing Allocation

We are on R12.1.2

I created an allocation rule for the Labor Clearing Account.  The source is the labor clearing gl account.  The target is all projects based on Total labor hours.

I created an expenditure type "Labor Clearing Alloaction" with a type clas of Miscellaneous Transaction.

When the alloactions are created as Miscellaneous Transactions, they are getting picked up for revenue generation.  We don't want that. 

Once created the Transaction Source "Projeccts Allocations"  will not allow me to make them non-billable.

Hoe can I clear the Labor Clearing Account without making the transactions billable.

Do I need to use an extension.