The original post is 7 months old so they might not need to know now.
I keep a Veiled and have to disagree with your post. They don't need dirt, they don't need a ficus, they don't need spraying every 3 hours.
The best substrate is no substrate. They don't live on the ground. Paper towel or newspaper will do fine if you want to use anything.
A ficus is one of many plants that can be used. Personally I use pothos. it grows fast and is vine like, so can be wrapped around the enclosure and it's safe if eaten.
Yes they need a decent humidity and don't drink standing water but to spray every 3 hours is very excessive. Twice a day for 5 - 10 mins at a time is plenty. In addition you could use a drip system for the drinking water or an automated mister on a timer.