The visitors had resumed with a 196-run lead and Dhariwal went to his maiden half-century from 107 balls in the third over of the day with a four off Red Rose skipper James Anderson.
Batting looked more comfortable than it had done on a frenetic second day when 22 wickets fell and he had reached 66 when he was well caught at slip by Anderson.
That concluded a ninth-wicket stand of 70 that rescued the innings from 86-8 and number 10 Matt Taylor had taken his score to a very valuable 31 before he was caught at third slip by Harry Singh.
It gave Gloucestershire a half-hour spell before lunch with the new ball and they took full advantage.
On-loan Somerset bowler JT Langridge yorked makeshift opener Matty Hurst for a duck with a delivery that wiped out leg-stump and would have made left-arm greats Mitchell Starc and Wasim Akram proud.
Ex-Lancashire bowler Will Williams followed on from his career-best 6-24 to remove Harry Singh for six before Keaton Jennings was also caught by Miles Hammond at third slip on the stroke of lunch for 16 off Langridge.
Flintoff, who scored a maiden List-A century last month, got off the mark with the first ball of the afternoon with a glorious straight drive off Langridge and his innings contained some superb shots and a bit of heart-in-mouth stuff as well.
He saw Marcus Harris caught by Hammond again, this time off Taylor for nine and then saw Shetty expertly stumped by James Bracey off Sai Kishore for six to leave Lancashire staring at a seventh defeat in nine matches at 64-5.
But the 18-year-old found some resistance with Ben Walkden as the pair put on 52 with Flintoff going to his fifty with a tickle for four off Williams, the eighth of his innings, which also included a controlled pull for six off the same bowler.
However, Walkden’s innings ended on 24 when India left-armer Kishore, bowling over the wicket, got one to spit out of the footmarks with Walkden given out caught behind.
That made it 116-6 and after one more Flintoff four, play finished with Lancashire needing 128 more on the final day to stop the bottom side from recording successive Championship wins.