Let me explain how that works in the real world — you drop all the tags/boxes/receipts for the merchandise, maybe apply some dirt, then you can claim that it's not new and you brought it with you from your home country originally. Also in the airport there is a rather high chance you get to go through the green lane where your bags aren't checked. There are certain manners that help with not being singled out for the bag check. How do regular people learn these? When you live in the corrupt country, you quickly learn how to look ordinary and not interesting to the authorities.