I would again assert that this is not needed for a successful marriage and can negatively impact said relationship and chances of a successful long-term marriage.
Truth is you dont need to know every disgusting, nasty or un-coothe thing your future husband or wife does. Whats important is that you not lose sight of the love you share and always do your best to treat them with the respect they deserve as your husband/wife.
You are right, you will learn things but those things are in no way truly important to a successful marriage.