These greenhouses are great to give your inside Hoyas a place to live in the summer. You can spray them down without worry of getting your furniture all wet, and give them lots of light. They can live outside without worry of the rain over wetting the roots and causing root-rot.
The drawbacks are the tents are without controls, and if you put them in a full sun location, they will act like solar ovens and quickly cook your plants. Even if you have the windows fully open, they will dehydrate your plants, and there simply is not enough humidity for Hoyas.
The only way these things work is to have a location where they will only get 2 to 4 hours of sunlight a day and even then it would be helpful if you could mist them with a hose a couple of times a day.