I can’t advise on humidity as it’s always damp here in Manchester Uk ..
That said ... I spray all the vivs on a random basis ( when it crosses my mind )
but I start spraying daily as soon as a snake goes into shed mode - cloudy eyes - disappearing out of sight for days- loss of colour ( apart from albinos /white snakes) .
Now once I notice the eyes have cleared and the colours are back to normal then start spraying well , two or three times each day .
You will find a messy , rolled up shedded skin lying around somewhere ( quite often under one of the hides)
100% success guaranteed
I only use orchid / reptibark as a substrate as it holds as much or as little as you require .
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