The film clean a delicated operation, any abrasion, or dry brushed damages the film.
To cleanig a film, the process is with special detergent, or neutral, diluted in water at 20 to 25 ºC. And, As soon as the cleaning has been finalized, should be rinsed in water distilled, until disappear the trace of detergent, so that thus, the process of dried leave not spots of detergent or of lime of the water, drying in a place without dust. (You can utilize adevelopper tank to clear the film)
The film endures perfectly 40ºC, if the filth is resistant, enlarges the temperature of the water.
Another solution, is to carry the film to a professional laboratory so that they clean it.