Can you tell me how oral contrast taste for ct scans?

Depends on the type: Oral contrast can be water, a barium based contrast, or iodine based contrast. It can taste like water, thick and bland, or like an herb.

Oral contrast: There are different oral contrasts, and there are different things to mix them with, so that is a difficult question to answer. Most people don't find it too bad. In the interests of full disclosure, however, in my experience no one has ever asked for more. :)