DouKaku?

using System;
using System.IO;

namespace Doukaku.CS
{
	public class DelNyoro
	{
		static void Main(string[] args)
		{
			foreach(string dir in args)
			{
				if (Directory.Exists(dir))
				{
					foreach (string nyoroFile in Directory.GetFiles(dir, "*~", SearchOption.AllDirectories))
						File.Delete(nyoroFile);
				}
				else
					Console.WriteLine(string.Format("Directory %s is not exists.", dir));
			}
		}
	}
}