There is a misconception about bathing a Sphynx. Over-bathing can create the very opposite of what you are trying to accomplish, and can cause over production of sebum (oils). The over production of sebum causes dirt to accumulate at a faster rate. I bathe my cats every 3-4 months, (unless in a show). Their Skin quality is dictated by several factors; genetics, diet, and environment. Feeding a balanced, raw diet improves the overall health, appearance, and cleanliness of skin.
Ear cleaning should be done regularly because there is no hair to protect, in and around, the base of the ear. I have found that Sphynx have a lot of yeast in their ears. This creates a lot of black goo along with the abundance of natural wax build up.
Weekly cleaning is recommended, however, I have discovered an ear cleaner that kills the yeast and helps to keep the ears cleaner much longer. I have been using this product for quite some time now. With this product I have found that I don't need to clean their ears more than once a month. Even longer for some of my cats.
The cleaner is called Posatex (see picture). It can be a bit costly. However, it is worth the cost because of the comfort it brings your cat.
Your kitten will be habituated to ear cleaning, bathing, and nail clipping when he/she comes to you at 14-16 weeks of age.