hmmmm..... I may be completely wrong here but here is my suggestion.
First. Stop using the solution. Throw it away.
I would open the humi and let it sit open for a couple days- hopefully it will dry out again.
After a couple days get a kitchen sponge that DOES not have a scent to it. Dampen it with DISTILLED WATER.
Plance the dampened sponge on some cellophane wrap and place it in the humi. Make sure the sponge isn;t directly touching the wood. Close the humi for 3 days and let it rest.
Check once a day to make sure the sponge isnt dry. If it is dampen it again.
While you are doing this salt test your hydro so you know it is correct.