Wales have lost five consecutive matches to the reigning Tri-Nations champions, including a 3-0 series whitewash this summer, but have the chance to end their drought at the Millennium Stadium in December.
Two of those matches went to the wire and 'Campo' reckons the Grand Slam champions should and could have won.
"Wales played a slightly under-strength Aussie side and blew the opportunities in front of them," the Wallabies legend Western Mail.
"Wales have the players but sometimes lack that cutting edge. They failed to deal with Pocock and it ultimately cost them. The Welsh need to commit more men to the breakdown to generate quick ball.
"After losing the first Test convincingly, Wales should have possibly gone on to win the series. The Australians showed, in the third Test, how to close a game down.
"If you watch the All Blacks play they are always in control. If Wales play that way they will start to win against the southern hemisphere. They will earn respect by playing hard."
Campese scored a record 64 times in 101 Tests on the wing for the Wallabies and reckons Wales must get a much ball as possible to their powerful wide-men George North and Alex Cuthbert.
But he is confident Australia will be even better, and a much tougher proposition for Wales, following the inaugural Rugby Championship.
"Wales need to give North and Cuthbert more ball. There needs to be less kicking," said the 1991 World Cup winner.
"The Welsh backs showed plenty of promise. They are a threat and they need to play the Welsh way. They need to get players to think for themselves, see space and utilise good skills.
"But the Aussies will improve after their Championship campaign. That should make for a fantastic autumn series."