But the dual Olympic champion says a dramatic overhaul of the squad's camaraderie and culture since the 'Stilnox Six' scandal is behind its rapid resurgence.

Hackett capped a successful comeback by making Australia's world championship squad, which won seven gold medals to finish fourth on the table.

It's a huge improvement from the hugely disappointing London campaign, which yielded just one relay gold and clouded by misbehaviour by the 4x100m relay team.

But with the likes of Bronte and Cate Campbell and dual world champion Mitch Larkin on the rise, Hackett can feel the glory days returning.

"The thing I've noticed is the effort that's been put in since 2012," Hackett said at a training camp at the Australian Institute of Sport on Tuesday.

"Obviously I wasn't part of the team back then but I was doing [TV] commentary and pool deck interviews, and I could see the fragmentation within the team.

"That was a bit disheartening but since then we've changed a lot of our support staff, we've got a new head coach [Jacco Verhaeren], a lot of things have changed for the positive.

"Being in Kazan for me felt like being back on the teams of yesteryear in terms of the camaraderie, the results we got and the attitude the swimmers had toward their performances and one another.

"There's a great bunch of people there who support one another, [there's] no one putting their hand up and thinking they're above everyone else.

"There's no double standards within the team, it feels just like when I was there in 2008 or 2004."

The Campbell sisters are swimming's new poster girls, with younger sibling Bronte sealing the 50m-100m freestyle double at Kazan.

The 100m final, where Cate finished with bronze in her return from shoulder surgery, was the first time Bronte had upstaged her sister at a major meet.

"It might sound strange but I don't swim to win gold medals," Cate said.

"I swim to get the best out of myself and I achieve a sense of euphoria after doing a really great training session and I remind myself that's why I'm swimming.

"[I don't] let my expectations, or expectations placed upon me, to get the better of me.

"While it wasn't my best meet I don't think you can come away with a bronze medal bitterly disappointed, especially coming back from shoulder surgery."

Bronte said her breakthrough meet had given her belief she can stand up to the more intense spotlight at Rio next year.

"It [beating my sister] doesn't make much difference, [it's more the fact] it's the first time I've stepped up onto a big stage and really performed," she said.

"It showed I can compete under pressure and obviously the Olympics are completely different to the world champs, but it's given me a lot of confidence.

Larkin was the one of the surprise packets at Kazan after winning the 100m and 200m backstroke, a feat backed by teammate Emily Seebohm.

His success means he won't be able to fly under the radar at Rio, a fact which has been hammered home by his coach Michael Bohl.

"He's reminded me of that quite often, Kazan was a great week but coming into an Olympic season the two guys I beat [Camille Lacourt and Matt Grevers in 100m] were the favourites and will be hungry for gold at what will be their last Olympics," Larkin said.

Seebohm added: "Both Cate and I want an Olympic medal for ourselves, and it drives me every day."