I have a horrible experience in DME about this when I connected from SIN...I attempted to bring duty free scotch back from SIN to IAH, border patrol/security stopped me and tried to take it away, finally got them to 'gate' check it, but had second thoughts about that, then just took it on...there may or may not have been a bribe of 100 Rubles...it was a fun time...also no one took the bribe of 3USD