First-half goals from Charlie MacDonald and Shaun Williams - either side of Kevin Lisbie's equaliser - plus late strikes from Jabo Ibehre and Daniel Powell ensured a convincing victory for the Dons.
MacDonald gave them a dream start when he turned in Mathias Doumbe's low cross at the near post after only three minutes.
Lisbie equalised for Orient after 13 minutes, bundling in Jamal Campbell-Ryce's corner from a yard as the Dons appealed in vain for a foul on keeper David Martin.
But Williams restored the Dons' lead 10 minutes later when he stole in unmarked to head home Jay O'Shea's pin-point cross.
Substitute Ibehre made it 3-1 when he tapped in MacDonald's parried shot from close range before Powell netted a superb solo goal to seal the rout six minutes from the end.
Dany N'Guessan eased any home nerves by putting his side in front after just seven minutes, and second-half strikes from Bradley Wright-Phillips and Darel Russell helped the Addicks home.
The Saddlers twice led through Jonathan Macken and Jamie Paterson, and despite Ryan Lowe's effort the Owls looked to be heading for defeat until Gary Madine fired an injury-time equaliser.
Wes Fogden's stunning 20-yard strike on the stroke of half-time earned
Rochdale's relegation fears intensified as
Goals from James Wallace and substitute Jake Cassidy gave Rovers the three points their performance deserved, leaving Dale five points adrift of safety in the League One drop zone.
Jean Ives Mvoto scored the only goal in a 1-0 win for