The Terriers were rocked by a stunning message from Chairman Dean Hoyle in Saturday's match programme over poor recent performances and they promptly lost 1-0 to Exeter in another stinker.
But Town answered the critics in style with a sparkling performance in which Rhodes, now the 10-goal top scorer, was the star turn.
He first pounced on a loose ball and let rip from 20 yards into the roof of the net after 47 minutes, and then slammed in the rebound after substitute Benik Afobe rattled the woodwork with a 66th-minute drive.
Antony Kay started the rout after 24 minutes when an Anthony Pilkington cross was deflected into his path inside the six-yard box.
Gary Roberts doubled the lead soon after with a close-range header after a Graham Carey corner was nodded back across the face of goal by Joe Garner.
MK Dons, outplayed throughout, got a consolation from substitute from Aaron Wilbraham when he raced through and finished just two minutes after replacing the ineffective Mark Carrington.