I'm just catching up with this thread and can answer a few questions. Becky asked from what country daylily rust originated. I'm not sure if the question is about where it originally evolved, or from where did it come to North America around the year 2000. The latter isn't known other than that it would have originated from somewhere in Asia and somehow ended up in Costa Rica as well. Daylily rust is native to several countries in Asia. The first official documentation was from Siberia in the 1800's but it must have been around long before that.
Becky also asked how a garden that has only grown daylilies from seed might have got rust. Since you're in Florida, it could have come in on the wind from other infected daylilies. To be sure landscape daylilies don't have rust you'd have to carefully examine the undersides of many leaves because a resistant daylily may not show many pustules. It is theoretically possible to bring daylily rust in on seeds from an infected garden, but normal seed starting methods would make it difficult for such rust to cause an infection even if the spores survived long enough on the surface of the seeds to remain viable.
For Ultra Dawn, I would agree to avoid antibacterial. For IPM scouting of turf we generally use lemon-scented "dish soap" because it is supposed to work better for insects. The procedure is to pour dilute lemon dish soap onto an area of turf and count the insects that it drives to the surface. I have to say that even with "regular" lemon dish soap it makes the earthworms very unhappy, they come out of the ground squirming and writhing. I don't know if it seriously harms them. I always have a sprayer of plain water with me to wash the soap off the turf so that it doesn't burn in the sun, and I always stop to wash off the earthworms as well, don't know if it makes them feel better but it makes me feel better that I tried to help!
For pest control I use a commercial insecticidal soap, like Safers, that is made specifically for plants. It is organic (OMRI listed) whereas "big brand" kitchen dish soap would not technically be considered organic if that's important to anyone (and is not really soap but detergent).
The article that mentions nickel not being effective on its own was the link that Michele gave earlier to the Dong, Jeffers and Buck article, which says: "Nickel has been reported
to reduce daylily rust development but it was not effective in our field trials". They did find it did better when combined with chlorothalonil, but I don't believe it was tested with any other fungicides so I don't know if one can necessarily extrapolate to a benefit in combination with fungicides in general. This research was also published in a shorter form in the AHS Daylily Journal of Summer 2011.
And that's my two cents worth
There are lots of other, newer, more recently tested and documented best-result chemicals ... but it would be hard for commercial growers to find them all in the various threads that go back over the years. A new, dedicated thread might help everyong to find and review them all in one place. 
