Byproduct in work order query

Hi,

Have been reviewing oracle documets regaridng how to transact by products in work order and got few queries if someone can help:

Setting Up Byproduct Information

Oracle Process Manufacturing (OPM) does not calculate the cost of production of byproducts.:

Q1)Does that mean if I add samples or rejects as by product there will be no cost associated with it. But then how do we absorb the cost for them or how do we adjust cost variance

Q2)Will  they show in inventory after work order is transacted

Q3)Do we still need to transact them at the end as move order issue to take them off the inventory or is there any other ways. Ideally I would like them to be removed from inventory once they are marked as reject/samples in work order .