The 26-year-old was invited down to the New York Stadium by United boss Paul Warne, and as well as training with the club, he also took part in a reserve team game against Port Vale.
"It went really well," said Taylor.
"I trained really well in the first two days and then I played in a reserve team game against Port Vale, but they actually put out the majority of their first team.
"We drew the game 1-1 and I made a few decent saves, which I'm happy with.
"Rotherham's manager Paul Warne was taking first-team training on the day of that game, but he sent goalkeeper coach Mike Pollitt down. He said I did really well and that he'd report that back.
"It is just a case of waiting to see what happens with it now. I might be invited down to pre-season, or that might be that.
"Whatever happens, it has been a great experience for me. At my age you don't expect to be given the opportunity to train with a Championship club.
"It shows you the levels you need to get to in order to make it in that standard of football.
"I'll come back to Scarborough on Saturday full of confidence, knowing that I can hold my own at that level and having picked up some hints and tips here and there that will improve me as a keeper."
Taylor will now be back between the sticks for Boro on Saturday when they take the trip to Buxton for an important play-off six-pointer.
He added: "Steve Roberts rang me on Sunday, we had a good chat and I'll obviously give him my full backing.
"There is no reason why, with the squad we have, we can't go on a run now and push ourselves right into the play-off mix.
"The lads were down on Saturday after the game, but we'll pick ourselves back up again and we'll be treating every single game we have left as a cup final.
"There will be twists and turns, but hopefully Lady Luck will be smiling on us at the end of the season."