Grandma told me to wash the tally wacker
Why would your grandma tell you to wash that?
Grandmama said I should wash my tallywacker thoroughly twice a day
I think it is good that you are on top of your bodily hygiene. You should thank your grandma for reminding you of that.
I also heard that I should use a special type of soap. My grandma said it is completely natural.
I have not heard of that, but you are listening to your grandma's advice, which is good.