My husband has recently painted a room that was newly plastered. He ignored the instructions on the paint tin which recommended sanding the walls and watering the paint down before using! He has used vinyl silk and the paint has peeled in a small area and peels off. However this isn't the case all over and in other areas is more difficult to scrape off. He is currently scraping this off with a wallpaper scraper (think its going to take until next christmas to remove) Does anyone have an effective way of getting this paint off more effectively and without causing damage to my newly plastered walls?