I'm not too familiar with this system http://www.citikitty.com/default.asp
but maybe others will have suggestions.
I can tell you from experience talking to others that teaching a cat to use a human toilet doesn't always work because it's not a natural thing for cats.
Yes, some cats can be trained to use it and I hope your cat will learn to use it - but some cats never do... I hope others have advice to share.