getstringkeys() is not a player function
you can however add it into a class which is joined to the player and it will accomplish the same thing -
PHP Code:
/*
you probably want to add some callstack checks here to ensure that only permitted scripts are calling this function, or otherwise only join this class to the player before you want to reset them
*/
public function resetClientrVars()
for(temp.key : getstringkeys("this.clientr."))
this.clientr.(@ temp.key) = "";