Dead mouse in Prius AC

Toyota shop noted cat and bird food in the air cleaner of our 2008 Prius( we recognized it). They replaced the filter and screened some openings. A few days later we began smelling what could only be dead rodent smell coming from dashboard vents - awful! They looked at everywhere they could but found nothing. To do a complete check will require removing the instrument panel, etc. at great expense. They said keep the windows open and it will eventually go away. I said no way, we can’t drive it that way. Our insurance adjuster says it will be covered by comprehensive if they find a dead rodent. If not, it is our problem. Our son suggests keeping a ripe, dead rodent on hand. What is your suggestion? (From what I can see online, Prius can be described as a mouse hotel!)

You have no choice unless someone can find something with a boroscope or mini camera.