No, you're right on that one. By the time the air becomes saturated enough with water to cause droplets to form, your ambient humidity is 100%.
I underestimated the ability of moss tohold moisture, so we're going to be taking another run at it just putting in dry moss and misting it down instead of soaking it first, then mixing it with dryer moss to distribute the moisture. So far it's worked well in one of the other rubbermaids... no condensation, but the air is still nicely moist.
- Ken LePage