Centre Sarginson, who is moving to the NRL next year, opened the scoring after five minutes while winger Charnley, who is switching codes with Sale at the end of the season, touched down twice before half-time to put the record 19-times Cup winners on their way to a comfortable victory.
Castleford never looked likely to repeat their 16-4 win over the Warriors in the 2014 quarter-final at the DW Stadium, with the contest over by half-time with Shaun Wane’s men leading 22-0, their other try coming from full-back Sam Tomkins, his first in the Challenge Cup since the 2013 final at Wembley.
The Tigers, who made a late change with Greg Minikin drafted in for his first appearance for two months in place of an injured Jake Webster, once more had prop forward Grant Millington filling in at stand-off, a ploy that paid off in their win over Salford in the last round but flopped this time.
Wigan, who defended resolutely throughout, never looked back after Ryan Sutton’s break created the position for Tomkins to get Sarginson over and Matty Smith kicked the first of his three goals.
The Warriors had some defending to do, with Sarginson stopping dangerous Tigers full-back Luke Dorn short of the line while centre Ben Crooks was held up over it, before Tomkins skipped past the flailing arms of Millington for his try.
Wigan survived a scare when Denny Solomona, Super League’s leading tryscorer, made a dive for the corner but was bundled into touch and they increased their lead with two tries from Charnley in the second quarter.
A midfield break from substitute forward Taulima Tautai set up the first as Charnley caught the Castleford defenders napping at a play-the-ball while his second came courtesy of a long pass from stand-off George Williams after Tigers winger Joel Monaghan rushed out of the line for an interception.
Trailing 22-0 at the break, Castleford’s last chance to get back into the game disappeared when Minikin broke through the Wigan line early in the second half but produced a poor final pass to his winger which was snapped up by Sarginson.
Solomona had a better opportunity when he gathered Luke Gale’s kick to the corner but Sarginson came across to tackle the winger into touch and the game became scrappy.
Wigan lost Sutton with a head knock and also appeared to lose their focus as the visitors took advantage of the lion’s share of possession to carve out a try for Gale, who supported Junior Moors’ break and added the goal.
The Warriors rarely had sight of the Castleford line in the second half and their only score came in fortuitous fashion on 66 minutes when Dorn was deceived by a wicked bounce from Smith’s grubber kick and right winger Dom Manfredi dived on the loose ball.
Manfredi appeared to miss the ball but video referee Robert Hicks failed to find enough evidence to overrule Chris Campbell’s initial decision, which once more highlighted a flaw in the system.
Castleford finished a well-beaten side but they at least had the consolation of wrapping up the scoring in the final minute when Monaghan flung the ball inside as he was being pushed into touch for Crooks to touch down and Gale landed the touchline conversion.