Propagating kiwi Help needed

I would like to propagate some hardy and some golden Fuzzy Kiwi (Chinensis). Both male and female.  Past attempts had only little success.  I want to try to do this again in my greenhouse under shade cloth and a timed spray irrigation system.

I plan on making a 2x4 box frame on the ground and fill with a potting soil professional growers mix.  Should I add vermiculite?  How about any other amendments?

Does anyone have any experience?  What are the on/off times for the spray?  Do you run 24 hours or 12 on 12 off?  What medium do you use?  

What about over winter?  Should I bring inside and put under grow lights?

I highly recommend  clean, sharp sand as a potting media. Other potting media are highly susceptible to promoting rot, and growing lot of microbes that will attack the kiwi.

I hand water my sand beds twice a day. An auto-timer or mister would be fabulous, but I can't recommend settings, other than to say that too wet is ever bit as much of a problem as too dry.

Thanks Joseph.  I was using a pond fogger and humidistat set to 80% and it was too much moisture.

I've had OK germination from seeds from commercial fruit - used a fermented prep as for tomato seeds followed by air drying.