I don't know if there's a minimum. With DD I used that stuff every time I went to the bathroom to heal faster and my midwife never said I could only use it X amount of times a day.
I switch between hemorrhoid cream and witch hazel as needed, but mine are pretty mild. I'd say I use the cream every 3 days and the witch hazel after maybe every other BM.
Re: Hemorrhoids and witch hazel