Wet cleaning or "washing" is well known procedure in paper conservation. It's a possible treatment for some photographs on paper support depending on condition and deterioration level of the object. In this particular case the main goal was to clean yellowish stains on the back and to reduce acidity in the paper. For washing process the following materials were used: Sheets of Hollytex, filtered water, proper washing container, etc. In the video you will see a series of activities, but don't forget that this is dangerous procedure. You shouldn't do this if you are not sure what could be happens and if you haven’t proper equipment tools and training. Added photos are showing some of the stages during treatment.
The photograph after washing, before mending the tear.
The weather outside corresponded to the “wet” treatments :-)