求翻译：四、洗洁精。先用干净的布将车窗内侧擦干净，然后再找一块干净的布，在布上倒入适量的洗洁精均匀涂抹在车窗内侧，可在短期内保证车窗不再起雾。不过这种方法一般只能维持一周左右，一旦出现雾气必须再次涂抹。是什么意思？

Fourth, the detergent. First with a clean cloth to the inside of the windows clean, and then find a clean cloth, and pour the right amount of liquid detergent on the cloth spread evenly over the inside of the windows in the short term to ensure that the window is no longer fog. However, this method