Cache
How To Clear Internet Cache Using C#
Cookie
An easy way would be to use Environment.SpecialFolder enumeration to get the Cookies folder and then Delete all the files inside the folder
public void deleteCookies()
{
DirectoryInfo di = new DirectoryInfo(Environment.GetFolderPath(Environment.SpecialFolder.Cookies));
foreach (FileInfo fl in di.GetFiles())
fl.Delete();
}
Credit goes to Clearing Internet Cookies In C#
Hope the above information helps.