Unilever and Revlon are sweating it out in the Federal Court over the efficacy claims of the newest clinical antiperspirant product to go on sale.
Unilever began court action against Revlon a fortnight ago to halt its rival's advertising campaign for Mitchum Clinical antiperspirant.
It claimed that the slogan ''nothing is stronger'' and promise to ''neutralise all odours'' were misleading and in breach of consumer laws.
Unilever had a 100 per cent share of the clinical antiperspirant market in Australia with its Dove and Rexona-branded products - until January, when Revlon entered with Mitchum.
The clinical-strength category is part of the broader antiperspirant deodorant market, which rakes in $380 million a year in Australia.
In May, Revlon began a magazine, television and social media advertising campaign, using the catchline: ''You thought nothing was stronger?''
Revlon's 15-second television commercial says: ''Great moments in life make you sweat. Enjoy them with confidence with Mitchum Clinical … Switch to Mitchum Clinical, the ultimate sweat plus odour control.''
Unilever retaliated, telling Justice Peter Jacobson that Revlon could not make the claim Mitchum was superior because its own research showed Dove and Rexona products were ''equally effective in controlling sweat and odour''.
Revlon's expert, Michael Traudt, did not directly attack this argument but instead said that the phrase ''The ultimate sweat and odour control'' was merely a type of puff regularly seen in ads.
Unilever also took issue with Revlon's use of the line ''oxygen odour control technology'', questioning whether the product even contained oxygen and, if so, whether it was at high enough levels to eliminate bad smells.
Dr Traudt said the formula for Mitchum included a stabilised hydrogen peroxide that neutralised odour.
Judge Jacobson dismissed Unilever's interim bid to have Revlon's ads halted while the case was still open and set the date for the final hearing next month.
Revlon marketing director Tracey Raso said the ad campaign was ''critical'' to the success of Mitchum Clinical in Australia.
So far, Revlon has clawed 7 per cent of the market, leaving Unilever with 93 per cent.
The ads will run until the end of this month.