I put the few I know to be summer dormant outside and water with caution. The heat and high humidity is dangerous for some touchy succulents. I suppose I have some that are summer dormant and I don't know it. Maybe those are the ones that rot and I am perplexed. :-\
I don't think I have any friends that would buy my plants. :-)
I recently received a summer dormant succulent in a trade. I was advised not to water during this time. I plan to keep my succulents in a dry sunny location where I can control the moisture they receive. I lost a lot of succulents last year due to excessive rain on top of our super humid climate.
Analogdog, Arn't most of the summer dormant plants from the southern hemisphere. The best plan, of course, would be to research the "in habitat" growing conditions of any particular plant and then use that information as a guide.
As a more general rule the southern hemisphere winter is at the same time as our summer. Knowing this, I would think that simulating winter conditions as best as possible would be a good general approach.
However, knowledge about rainfall in the plants' native habitat would still be critical. Does it get winter rain or summer monsoonal rain or just heavy fogs? You also might have to make an effort to keep the dormant plant cool.
I don't intend any of this as instructions, but only some things for you to think about.
Oh, I did the reseach, and have one, Pelargonium alterans that needs to dry out in the summer or look non-desert for a P. alterans. I have been thinking about just keeping it out with the others with a big no water tag. Or maybe as part of a group of no summer water plants.
AnalogDog, I sometimes go to a site called growing tropical plants in Tucson. It also comes up under desert tropicals. It has useful information developed for growers in that area. I find that often the info. is useful eventhough it is specific for that area. Let us know how your planned care works out. Don