The present invention relates to a composition, in particular cosmetic, comprising: (a) at least one synthetic phyllosilicate with molecular formula Mg3Si4O10(OH)2 in the form of an aqueous or hydroalcoholic gel and (b) at least one electrolyte and/or at least one polyelectrolyte. The present invention also relates to a method for cosmetic treatment of the skin and/or nails, comprising the application of said composition to the skin and/or the nails, as well as a cosmetic method for treating perspiration and possibly body odour linked to human perspiration, in particular odours from the armpits and the feet, characterised in that it consists of applying said composition to the surface of the skin and, specifically, to the armpits and/or the feet.