Humidity controlled drying box idea

Have you guys seen this:
It's called a Willhi WH8040, $25 on Amazon. They're on eBay too. The photo is deceiving, it's very small. ~3" wide, 1" tall. It will turn on a fan or dehumidifier when the humidity reaches a selected level.

It has a number of useful features:

• Non-volatile memory. It retains settings after power loss.
• Configurable hysteresis (the amount of humidity change before the fan turns off. 1% to 30%).
• Protective timer (the amount of time which should elapse before the fan turns on again. In case you don't want it flipping on/off a lot. More useful if you had a 1% hysteresis.).
• Calibration function.

I got one and it's pretty neat. The sensor is very sensitive. My humidity is 34%. I can blow in its general direction and it immediately rises to 35-36%. I exhale directly onto it and it jumps up to 65%. Consumes 2 watts.

I'm thinking about making a drying chamber. A large plastic tote or a 2x2 tent with a computer fan mounted on the side. Use this humidity controller to turn on the fan when the humidity is > 70%, off when 68%. Do the bulk of drying (from 90% down to 68%).

I thought I'd post this in case others have ideas.