To remove fingerprints and strokes from photos using the water method, follow these steps:

1. Prepare a basin of water.
2. Place the photo in the water and gently wipe it with a cotton swab or paper towel.
3. Be careful not to rub the photo too hard.
4. Remove the photo from the water and paste it on a mirror to dry.
5. Use a hair dryer on low or medium heat to dry the photo.
6. Be careful not to hold the hair dryer too close to the photo.
7. Once the front of the photo is dry, remove it from the mirror and dry the back of the photo in the same way.

This method can also be used to remove tomato juice and milk liquid from photos. However, it is not effective for removing stains such as black tea and coffee, especially in lighter-colored areas.

The water method is not suitable for photos taken with digital cameras, as the photo paper used is different.

Additional tips:

• Always test the method on an inconspicuous area of the photo before using it on the entire photo.
• If the photo is very dirty, you may need to clean it multiple times.
• Be careful not to soak the photo in water for too long.
• Dry the photo thoroughly before putting it away.

With a little care, you can use the water method to remove fingerprints and strokes from your photos without damaging them.