congress' approval vs. congress's approval: a thread to hash out the possessive 's s'

googling around I thought this made sense: boys' ball (a ball owned by two or more boys) v. boy's ball (a ball owned by one boy)

And Beuys's ball (a ball owned by Joseph Beuys)

Boise's ball (a ball owned by the city of Boise)

While I am well aware of the approved standard I was taught as a lad, this is definitely a standard I think ought to be rescinded. Every way of handling a possessive "s" following a terminal "s" will be ugly, but at least "Charles's" has the twin virtues of being easier to notice and easier to remember, because it isn't a deviation from the general rule.