Impossible to Stop.  Governments might as well accept that allowing retailers to sell grey goods has benefits because government will never be able to completely prevent such imports. Government regulation may prevent most retailers from selling grey goods but it won't stop all. For example Tesco in the UK sold cut price Levi jeans for years, and fought Levi Strauss in the courts for four years to try and keep selling them.1 If even the biggest retailers are willing to sell grey goods unless stopped by the courts many smaller ones will be getting through the net. Moreover consumers will simply buy the goods elsewhere, particularly online. The government should instead legalise the import of grey goods so that it can make sure that these imports are of a high standard and do not break any other standards  1 BBC News, 'Tesco defeated in cheap jeans battle', 31 July 2002,