I have a bunch of Park Models that I rent out here in Yuma . I turn off the elect, water for 7 months. I also leave 7 or 8 gallon milk cartons thruout
the Park Models and Houses with water in them. I cover all the windows, toilets,
all drains in sink, shower etc I have been doing this since 2000. Works for me.
We also leave two cars here for 7 months. I make sure batterys are charged up,
I disconnect the battery. Come back in Oct and cars start right up.
The cars are under awning cover with 3 car covers over them and still get dust in and over them