I have even a better suggestion , Let the 3rd umpire decide and declare out without bowler removing the ball based upon whether the batsmen is inside the crease or outside when the bowler delivers the ball , That way there will be no such incident of cheating by the batsmen and bowling side will also not feel shame by Mankading him nor there will be any incident when bowler initially stops and wait for the batsmen to get outside the crease and mankad him , Will make the game more simple.
In a nutshell if the batsmen is outside his crease when the bowler delivers the ball then he will be declare out automatically by the 3rd umpire. This rule will practically remove such incidents from the game as no body will want to get out this way.