Although the final scoreline flattered the hosts somewhat, with 26 of their points coming in the final third of the match, Gentle was happy with his team's efforts in a match which saw several youngsters take advantage of their chance to impress.
One of them, 20-year-old Jamie Shaul, grabbed one of two Hull hat-tricks in the match, with the other coming from veteran centre Kirk Yeaman, and Gentle said: "The main thing we can take from today was the amount of game time we got into the younger blokes in the squad."
He added: "In the cup, winning is all that matters and we've got through to the next round, but a big positive for us was the experience the youngsters gained in playing in that sort of environment.
"When you looked at our team sheet and saw the number of players wearing number 20-something on their back, it gives you a fair idea of the number of people we had missing. The guys out there did a terrific job and we've come through relatively unscathed, so we are pretty pleased."
Gentle did concede his side were not at their absolute best for the whole 80 minutes at the KC Stadium, though, adding: "We were probably guilty of losing our concentration a few times but we got the win and that's the main thing. It is hard to stay in these games and keep your concentration up.
"I thought our second half was better than our first. We were guilty of panicking in the first half."
Crusaders coach Clive Griffiths felt his team were hard done by regarding the high penalty count against them, but praised his players' effort and the loyal travelling support.
"I was proud of the effort the boys put in. People might take me away in a straight jacket but I didn't feel that was a 60-point game," admitted Griffiths.
"Our fans were outstanding and I think even at the end the Hull fans were chanting our name. We are desperately disappointed with some of the things that happened out there which were beyond our control. It will be hard to get back up again on Tuesday [against Hemel] but we will make some changes because a few of the lads have picked up injuries."