I'm trying to get my humidity up between 60 and 70% for my Central American Boa; so far i'm just misting many times a day (ambient room humidity is 40%). I have a patch of moss that holds a bit of moisture, but its messy and will rot soon. I have a 27 gal sterilite, roughly 34 long by 14 deep by 12 high with a generous number of air holes around the perimeter about 3 inches up from the bottom. Heat source is an 40 watt radiant heat panel above (78 degrees at ground level on the cool side, 84 on his elevated perch) and UTH on the warm side (92 degrees). I use paper towels for substrate, I know coconut husk andy cyprus holds humidity better but i'm not into the cost and maintenance it requires at this time. Reptifogger type devices seem to get terrible reviews for durability though homemade hacked humidifiers look interesting (i'm definitely tinkerer), but seem over complicated and i also worry they may produce too much humidity.
so i had an idea and i'm looking for feedback.
A dripper (think zoo med little dripper) with a slow drip onto a sponge (natural) sitting on part of the hot spot. I use distilled water, and of course will sanitize the sponge a few times a week. I know it wont be terribly attractive, but my setup is not meant for display, just comfort. I like the simplicity of this idea; once i get the drip to evaporation ratio dialed in i feel like there is very little that can go wrong.

What do we think?