zapper effect on stainless steel

i've been using zapper for 2 nights now.. cant say it's working against
my Seborrheic Dermatitis .. i do notice that my feet doesnt smell
as it used to be..
but it's too early to say..

my question is i plan to use zapper during the day;
however, i have a stainless steel wrist watch..
i've read that steel and zapper is not good..

any comments?

thanks,