There IS a way where you can have a rule which allows a player to "un-castle." All you have to do is have non-standard chess.
The basic rules of standard chess have been in place for hundreds of years, since between 1400 and 1600. The rules changed considerably during that era. Instead of 8X8 boards they sometimes had 12 X 10 boards. They also had additional pieces, the Prime Minister being the most famous.
In modern times we have non-standard chess such as chess 960, bug house, crazy house, bracketer, Brigham Young chess, fairy chess and so forth. We have unusual pieces introduced, such as the Chameleon which captures by means of the normal move of the peace it's capturing. Or, the Grasshopper which moves like a Knight, but bounces in a line all the way across the board.
Therefore, all you need to do is, when you are playing your friends, introduce your rule of un-Castleing. Be sure to write it down first so you have an official rule agreed upon among your friends.
How many times would you be able to castle in a game?
EXACTLY !!....play some low-level tournaments w/ the Uncastle option & see how it's accepted. I mean you can't just drop Uncastling into world class play. It'll freak everyone out.
)
still not know