Howto smuggle things to UK

I've just returned from Belfast. Nice small city. But every pub and most restaurants have bouncers standing near the entrance, and there are a lot of people that look tough (but still friendly).

I've just found a nice way to smuggle things to UK. So, you arrive from Russia to Heathrow terminal 1, having no checked-in luggage(recommended), and some polonium marijuana 10 bottles of duty free vodka and 5 blocks of Marlboro in your backpack. You follow the sign "connected flights" and go to the security control for transit passengers line. Then there will be immigration (smaller comparing to usual T1 hurdle). If London is your final destination, there is a place where you can step over a low fence and go with domestic arrival passengers and thus skip customs, or you could board a domestic flight to non-international airport, that also lacks customs.

One local friend of mine told me once that customs is a very respected and mighty organization in UK because once in 90s it even prosecuted a MI6 agent who smuggled things working undercover on assignment. I wonder how it allowed this strange hole in Heathrow to exist.

I will not even try to exceed the allowed quantity of duty free goods because I am in some other business and I believe in the economic power of specialization. I do not recommend it to anyone either because apparently it violates some law, but I can hardly think of the way to prove it.