While looking for information concerning the safe cleaning of celluloid I happed upon this webpage.
JAIC 1991, Volume 30, Number 2, Article 3 (pp. 145 to 162)
Lots of interesting things to say about preserving celluloid objects.
Water of all things isn't good for celluloid apparently.
Dry your razors gentlemen.
Further it is my understanding alkali will deteriorate celluloid quickly. Soap can be alkali.