35mm – What is the best liquid to wash old negatives?

I've been digitizing old family negatives, mostly 35mm since the 1970-1990s and I'm trying to eliminate as much dust as possible.

I would like to be able to wash the negatives in water, of all the methods I have tried (several alcohols, blowers, wipes), this is by far the best work to eliminate the dust embedded in the emulsion, but I have read that water wash will destabilize the dyes, and should be followed with a stabilizer that contains formalin.

As I understand it, formaldehyde in formalin is blocked in the gelatin around the dye stains in the older colored films, and also has antifungal / antibiotic properties, which prevent the damage of mold growth.

A recommended product, Kodak Flexicolor Stabilizer III, seems to be no longer sold. Does anyone know of a substitute who would do the same?