I remember when i was selling a Mycelium entropy usb devise and a lot of people commenting were put off buying it because they thought it may have been tampered with in a way, that was even after i pointed out that you could update the device and add your own entropy by changing the "salt"

You will probably get similar questions i thought.
I have not used a trezor yet so not familiar with them, can the Treazor be "cleaned" completely so it is just as safe if straight from the factory and this checked?