My opinion; it should be OK to spray the non-irrigated property with the mixture you suggest at label rates.
Here is a photo from a test using Quicksilver and various herbicides--but the test was conducted in late May. It probably was a more favorable time for treatment, a time of rapid growth. The full rate of Quicksilver was probably a help, too.
It is difficult to evaluate the long-term success, as Quicksilver is a contact-type herbicide, and as such it probably does not do much to the roots and rhizomes of the violets.