Do you think cleanliness is associated with your business success?

It's not so much about being clean, as about being organised and efficient. If your desk is covered in piles of paper and dirty coffee cups, it will take you far longer to find that vital piece of paper that you need, which reduces the amount of time you could be doing something useful. Similarly, if you're concentrating on something, having a bunch of dirty coffee cups in your line of sight is distracting, which will slow you down. Minimising your distractions, and knowing exactly where to find things quickly is always helpful, and a good habit to get into. If you're in a shared office space, it's polite to keep your desk clear so that it's not distracting others. A side effect of a clear desk is that it's easier to keep clean as well!