The humidity in our house generally runs about 55-60% and 60-65% in our cages - without any work. During Santa Ana winds our humidity drops down into single digit numbers and I soak the cages to keep the snakes happy but other than that and a spritz during shed time - my cages maintain 60%. I guess it would be dependant on where you live as to how much extra work you have to put into keeping you humidity up.
If you are having a hard time maintaining a good humidity you can try cypress or reptibark (orchid fir) both of them are mold resistant and good with humidity. As a side note - I ran my maternal incubation tub last season at 100% humidity for 2 weeks and saw no mold on the aspen.
In my experience I've never had a snake use a humid hide - but I know people swear by them.
Hope this helps.
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Tosha 
"Nihil facimus sed id bene facimus"

11.42.0 Ball Python (Harry and Fluffy and gang)
1.0.0 Angolan Python (Anakin Skywalker)
0.0.1 Green Tree Python (Verdi - yeah I know but my kids love the book)
0.1.0 Bredls Python (Smurfette)
0.2.0 Feline (Pippen and Pandora)
0.0.1 Desert Tortoise (Pope John Paul aka JP )
2.2.1 Fish (1,2,3,4)
0.0.0 frogs rescued from pool skimmer