Mourinho was the ultimate host, greeting United as they arrived at the ground and personally giving the entire squad a guided tour.
And after seeing his expensively assembled squad edge past Scunthorpe, he waited for the Iron players to take their plaudits from the 6,000 travelling fans before shaking every player by the hand.
Iron boss Brian Laws said: "He made our players feel very, very special. It's easy for big clubs and big managers to ignore the smaller teams, but he treated us like kings and we nearly took a ransom.
"He's a very nice man. I know he comes across as arrogant and big-headed - like my old boss Brian Clough - he's got the personality of Cloughie, he was very nice and complimentary. Cloughie was a legend, and Jose will go on to become one.
"I can only praise Jose for his hospitality. He came in the dressing room and handed over his report on us from our previous match."
Mourinho was so entranced by the occasion that he even called for the Cup to be changed, so that smaller clubs get to host Premiership sides.
He said: "Maybe they (the big clubs) would lose, but that is the risk. What it would do is allow the romance to those places, and allow people a memory who never get to see the top stars.
"I have a lot of respect for these guys (Scunthorpe), they had a dream to come here and win and that's what they went for.
"Had we played at Scunthorpe maybe we would have lost."
After the game, United's players went into the home dressing room to meet the most expensive footballers in the world, and collect mementos from the day.
Cleveland Taylor, who came so close to scoring a second-half equaliser, said: "I got Wayne Bridge's shirt, even though he wasn't playing, that's how nice they were.
"You always hear about big-time Charlies, but you don't really know what people are like until you meet them yourself. Everyone at Chelsea has been fantastic."