I don't have a hot box, but we did get a good dehumidifier for the house awhile back due to high humidity levels and allergies/asthma. I try to keep the house under 40%, and since i got it i bring my staves that I'm tillering (esp hickory) inside for 24 hrs before i do any work on them. Seems to have made a big difference. I keep all my finished bows in the house of course.
Okie you may look into getting one (though a hotbox would be cheaper!!!).