12551 Yesvantpur Kamakhya Superfast Express is one of the dirtiest trains. When we boarded the A1 AC two tier coach on January 3 morning, the coach was littered with plastic packs, potato chips packets and tea cups. Cockroaches were running all around. The toilet was stinking with crap clogging the hole. There were no signs of any train staff coming to clean the toilet. It seemed the train staff have not been paid for years together. The bed rolls are not clean either. It's a train you must avoid like plague.