Disobedient cat

Question
My wife and I have 2 cats.  I have married into them.  Bother and sister.  The female overall is a very well behaved cat.  The male on the other hand...  he knows where to go to the bathroom but many times will poop right next to the litter box.  I thought maybe it was because it wasn't clean, so we tried cleaning it more often, didn't help.  We tried 2 litter boxes, on the advice of others... No help.  I know he knows it's wrong because I have tried punishment, similar to that of a puppy, rub their nose in it and give them a little swat on the butt and tell them it's naughty... nothing.  He does know it's wrong though because he will not do it unless he thinks I am going to be up after my wife and when I'm not home.  He will do it when my wife is home.  Many times I get up and I am out the door before her and he will wait until I am gone and then poop right next to the litter box.  I am at the end of my rope.  It is almost to the point I am going to have him put down but I don't want to do that to the female (his sister) because she would be lost without him.  He also like to splash water out of his water dish, when I am asleep, in the bathroom or not home.  He will not do it when I am within the line of sight.  Thank you for your time and I hope to hear back from you soon.

Answer
Mike,

Cats do not respond well to negative reinforcement, i.e. discipline.  What may work for puppies generally will not work for cats.  Have you changed the type or brand of litter?  Cats can get very particular about the litter in their litter boxes.

The two litter pan idea may not be a bad idea as long as they are not right next to each other.  Is it possible the female is not letting him go in the communal litter pan. Cats do have a pecking order with respect to litter pans.

Has the male been checked for any possible medical issues such as worms or impacted anal glands?

A solution may be to put the litter pan on a plastic, easily cleaned tray so that any mess is minimized.  

Please let me know what happens.

Best regards... Norm.