Yes there is an automated set up that will take care of the situation for even up to a month!
It's the basics of a shotgun terrarium set-up using a mineral like
perlite to slow-release water into the air. It just requires an almost-sealed chamber, with only some ventilation holes (always best to put a screening/filtering material there) for gas exchange.
The perlite is like kitty litter sitting at the bottom. About 3-4 inches should be enough for up to a moderately sized chamber. The perlite first needs to be wetted thorough, then excess water needs to be strained. This loads up the mineral with water in all holes/cavities. The more perlite, the bigger the total water capacity is.
Evaporation gets the air humidity in the chamber you use plenty high, like 90-95% or so IIRC. Maybe a little lower, it may tend to yield shrooms that have rupturing cap edges but other than that growth is fine. For perfect humidity I guess things like ultrasonic humidifiers are needed but the above technique is enough to do quite well. Not as an emergency solution but in general. It's what I did, apart from 1 kit I once used.
FYI perlite is used as as a soil constituent so it should be available from farming/grower sections of big stores - or more specialized ones. Here in the Netherlands I need to get it online (expensive) or from a farming store (cheap but you get a 100L bag, it weighs surprisingly little though.. being so porous and all). In the Nothern America region where there is big ...-Marts I don't know what the best play is.
can I consider this answered?
