Rovers fielded 10 trialists, including former Tigers duo Jordan Tansey and Ryan Bailey, who was sin-binned late in the first half following a clash with Robbie Storey, who was also shown a yellow card.
Tigers included half a dozen first teamers along with some fringe players and a host of youngsters and ran in 11 tries - eight of them scored by wingers.
Gill, who will spend 2019 at Newcastle Thunder on a season-long loan, touched down for the game’s opening three tries inside the first 26 minutes.
Stand-off Corey Aston linked with Joe Wardle and then Peter Mata’utia and Tuoyo Egodo for the first two before Wardle’s pass created the third.
Aston converted Gill’s hat-trick score off the touchline to make it 14-0, having missed his earlier two kicks from the same place.
Proving there is no such thing as friendly rugby league, Bailey and Tigers’ Robbie Storey were sin-binned following a skirmish just before the break.
The penalty went to Castleford and there was time for Greg Minikin to send James Clare, Tigers’ right-winger, over for an unconverted try on the final play of the half, making it 18-0.
Gill went off at the break and his replacement, Carr, scored the first try of the second period from Callum Turner’s long pass after Aston had again handled. That came seconds after Jake Sweeting had touched down from Tuoyo Egodo’s kick, but he was offside - only for Tansey to fail to find touch from the penalty.
Sweeting sent centre Greg Minikin over in the next set and the next try came through Clare after a flowing move involving Matt Cook, Sweeting, Turner and Minikin.
Aston converted that one to make it 32-0.
Egodo had a fine game and created the next touchdown for Carr, on the hour mark and Sweeting capped an impressive performance by sprinting 80 metres after a Rovers attack broke down deep in Tigers territory.
Turner weaved through some tired defence to score the 10th try four minutes from time. In the final seconds Turner sent Carr in to complete his hat-trick and Aston landed his sixth goal with the final kick of the game.
See Monday’s Yorkshire Evening Post and online for a more detaiiled report and reaction.