Can one tovel a utensil on tisha bav? If someone needs to tovel a juicer that has 2 metal attachments, is the bracha kelim in the plural, or keli in the singular? One untensil, 2 parts that are attached when in use, but separate when taken apart.
It is permitted to tovel a utensil on Tisha Be’Av. Although this will imply getting one hands wet, there is no prohibition of getting hands wet, but only of washing the hands. Immersing items in the mikva is not considered washing hands, and it is therefore permitted.
This is similar to washing a baby, or washing food, where there is no need to be careful that one hands won’t get wet. Only washing for the sake of pleasure, or netilas yadayim, is permitted, and not other ways in which hands get wet.
Because the two metal parts are part of one utensil, the berachah should be al tevilas keli.