Dust for a sensitive chin.

I have a chin who earlier this year started getting watery eyes. Her teeth have been checked out and she eats fine, actually she's a piggy sometimes.

I think it may be the dust baths, because they seem to only occur after a good bathing, so I've been giving her fresh dust every time and it's still not helping. I'm wondering if anyone else had this issue and what kind of dust to use? She's currently using Oxbow Blue Cloud.