Houston said: "What happened to Willo should serve as a timely reminder.
"I know the lure of Celtic for a Dublin boy was just too much for wee Willo.
"But from talking to him all the time I soon realised that within three months of going to Celtic, he would have much rather stayed at Tannadice.
"He took a step back joining Celtic from United where he was playing first-team football. He had to learn the hard way.
"Conway, for his part, is still learning the game. For me, it wouldn't be stupid for him to stay here for another year to progress even further.