Michael Oakes denied Steve Sidwell with two impressive saves early on before Colin Cameron calmly stroked in Wolves' first after a pass from Carl Cort.
Seyi George Olofinjana made it 2-0 but Dean Morgan beat the offside trap to pull one back from Ricky Newman's pass.
But Clarke nipped in ahead of Ibrahima Sonko to poke in a third and completed the rout with a cool finish at the end.
Wolves caretaker boss Stuart Gray on the managerial vacancy at Molineux:
"I've been in the game long enough to know these things take time. This is a big football club and there will be a lot of top names that want this job.
"I've probably given them a bit more time with the results regarding
them having to make a decision.
"If they want to go into a second round of interviews that's entirely up to
them. All I'm concentrating my efforts on is winning games of football.
"If the new man wants to bring in his own staff it might mean goodbye to me. I've got 18 months left on my contract and I'm sure I'll be seeing that contract out."
Reading boss Steve Coppell:
"This was an embarrassing result for us and our away form is obviously
becoming a concern.
"It's looking like a pattern which we can't accept. It just proves that this
division is not about the best XI but the best squad of players.
"At 2-0 down I still thought we could go on to win the game. It says a lot
that in the first half their best player was the goalkeeper.
"But we let ourselves down by committing defensive errors. It's imperative
that I get a defender in this week, either on loan or permanently."
Wolverhampton: Oakes, Lowe, Craddock, Lescott, Kennedy,
Cameron, Olofinjana (Naylor 69), Andrews, Cooper, Cort,
Sturridge (Clarke 60).
Subs Not Used: Murray, Seol, Miller.
Goals: Cameron 31, Olofinjana 45, Clarke 77, 90.
Reading: Hahnemann, Murty (Newman 20), Sonko, Ingimarsson,
Shorey, Little, Harper, Sidwell, Hughes (Convey 81), Morgan,
Kitson (Owusu 45).
Subs Not Used: Brooker, Young.
Goals: Morgan 47.
Ref: S Bennett (Kent).