Mundine didn't waste time after his Friday sparring session to take aim at Horn's camp for claiming he may be tempted to take prohibited substances to make weight, starting his press conference in the make-shift ice bath.

In unusual scenes, bemused media gathered around as Mundine fielded questions recovering in the bin at the Logan Boxing Gym situated in a Slacks Creek backyard shed in Brisbane's west.

But the ice his father and trainer - boxing great Tony - poured into the bin certainly didn't cool down Mundine, who unloaded on Horn's trainer Glenn Rushton.

Rushton said this week that Mundine may be tempted to take "short cuts" like diuretics or prohibited substances to make the 71kg catchweight bout at Suncorp Stadium - supposedly the 43-year-old's final fight.

"That's bulls***. That really p***ed me off even bringing that s*** up," Mundine said.

"I am probably the most drug tested person in Australian sport, for real.

"I tell kids 'don't touch drugs'. I don't even like taking cold or flu tablets."

Rushton revealed under their fight contract Mundine could be blood and urine tested up to five times before the bout to make sure the former NRL star was losing weight "properly".

Mundine, who fought Danny Green last year at almost 91kg in cruiserweight, is believed to be trying to come down from 80kg.

Horn, 30, has fought most of his career at the 66.68kg welterweight limit.

Also under the strict contract, Mundine will have to pay a fine of $20,000 per 100 grams for the first kilogram he is over the 71kg limit and then $500,000 for every kilogram after that at the weigh-in held on the day before their fight.

Mundine (48-8-0 record) and Horn (18-1-1) will be weighed again two hours before the fight where both must be 75kg or less.

Mundine said he agreed to the stipulations to get the fight done because he believed it was what the fans wanted to see.

"It is going to be hard. They want to try and make me as vulnerable as I can be," he said.

"I am making sure I do everything in my power to be as physically strong as I can be."

Mundine eventually got out of the bin to answer questions but it wasn't the end of the trash talk.

"He's a good kid but he's not in my league," he said of Horn.

"He can't trash talk. He is like watching paint dry, he is that boring. And he is a boring fighter - I am appealing to the eye."

Australian Associated Press