Je part d'une simple analyse de desalterant qui signifie: qui desaltère, qui abreuve, qui apaise, etc et je dis, la peau est sèche et le melange à l'eau desalterante aide à la rehydrater

Eau de gloss désaltérante rose de Bourjois. lLa texture fraîche, non collante et hydratante d'Eau de gloss, enrichie de nacres, se fait précieuse.


ou bien hydrating water comme proposé par Julie

When I did my beauty therapy course we used rose water or orange water to mix with the powder to make face masks. These waters are slightly scented and less acidic than tap water. Distilled water could be used if the client has sensitive skin.
Needless to say, the quality of tap water varies from area to area. The therapist would chose a suitable water for the mixture taking in to consideration her tap water supply and her client's skin type.

my suggestion - this is the only possibility I can see...