Gentle is hoping to become the latest Australian to make his mark on the 116-year-old competition when his team take on favourites Wigan at Wembley on Saturday.
"It is unique and a big attraction," Gentle told a press conference in Manchester. "It is something the NRL miss out on.
"I don't know how they'd fit it into the schedule but it's definitely something they miss out on.
"I think it's a lure for NRL players to come here, to play in this competition and to get to play in the final at Wembley is one of the greatest achievements you can get in our sport."
Saturday's clash has revived memories of one of the greatest finals in Challenge Cup history, the 1985 decider in which Wigan beat Hull 28-24 with Australians Brett Kenny (Wigan) and Peter Sterling (Hull) playing starring roles.
Current Wigan coach Shaun Wane was a Wembley winner as a player with his home-town team in 1998 and, after being assistant to Australian Michael Maguire when the Warriors lifted the trophy two years ago, admits Saturday will be one of the proudest moments of his career.
"To get the chance to lead my home-town team out is really special," he told the press conference. "I'm going to enjoy the day and hopefully going to enjoy the game as well.
"The past times we've played Hull have been really exciting games. They are two teams who play fantastic rugby league so it has the makings of the classic it was in 1985.
"I've seen a lot of Hull this year and, credit to Peter, he's got them playing a fantastic brand of rugby league."
While Hull go into the final on the back of three consecutive Super League wins, Wigan are on the slide, having lost five of their last seven league games to drop to third place in the table - but Wane insists form is irrelevant.
"I'm not concerned at all," he said. "On any given day, we can play.
"We're not attacking as well as we can at the minute but you get those blips in the season.
"I am confident that, with Lockers (Sean O'Loughlin) back and Blake (Green) and Matty (Smith) firing, we should be okay."
Skipper O'Loughlin was Wigan's only absentee during Saturday's 22-8 defeat by Catalan Dragons in Perpignan but Wane expects him to recover from a calf injury and says full-back Sam Tomkins came through his first league game for almost two months unscathed.
"Sam played played the full 80 minutes and he's good to go," Wane said.
"Lockers is hopefully going to train tomorrow and I'll have more of an idea then.
"I'm pretty confident. He's desperate to play, being a Wigan lad and captain. To lead his home-town team out at Wembley means a lot to him.
"We had a tough weekend, travelling over to France. We've lost a day but apart from that, the lads are looking forward to this weekend.
"We'll train tomorrow and I've have a look at the knocks and bruises from the Catalan game."
While Wane expects to be able to field a full-strength team, Gentle still has a number of injury concerns.
Full-back Shannon McDonnell, back-row forward Ben Galea and centre Ben Crooks are definitely out and winger Tom Lineham remains doubtful, although he had a light run on Monday.
Gentle has still to make a decision on centres Joe Arundel (ankle) and Kirk Yeaman (hand) and second-rower Danny Tickle (leg), who were all hurt in Friday's 18-13 win over Salford.
"We had three quarters of the squad able to train this morning," Gentle said.
"We're going to have to make a decision tomorrow afternoon on who plays.
"At the moment they're all putting their hands up to play but we've got to be smart about it. We can't afford to get an injury early in the game.
"Everyone needs to train tomorrow and we'll make a decision after that."
Gentle, too, is taking little notice of Wigan's poor league form, pointing to his own team's experiences in the Cup this year.
"I think both sides have proven that Super League form means nothing in this competition," he said.
"We beat Catalan and Warrington of the back of very poor form in the competition. We know what Wigan are capable of. I think it should be a great game."