Is Epsom salt a good desiccant?

Answer 1

Yes. As any salt is something that will draw water from whatever you put into the salt. Plain salt may do better. You can find coarse salt used for desalting sidewalks that will work just as well.

Answer 2

Epsom salt is not a good desiccant as it is hygroscopic, meaning it absorbs moisture from the air but does not have a strong capacity for removing moisture from materials. Other desiccants like silica gel or calcium chloride are more effective at absorbing moisture.