Both heat sealed and vacuum sealed are air-tight, so that difference should be a non-issue. Its the stuff sticking to the outside of the bag that might be an issue. For meat I'd imagine bleach should do the trick...no idea what you'd need to remove drug traces though. Not a skillset I plan on deploying anytime soon so didn't research it.
The majority of the buyer are going to buy on feedback. And a US supplier using fake Netherlands location is likely to get good feedback based on fast shipping (seeing how its fake Netherlands) and gain the benefit of the "positive" Netherlands connotations (Hollywood's view of the Netherlands in the average person's eyes).
4th amendment - true but not relevant to an environment dominated by non-lawyers and buyer's reviews I think.