There are two kinds of dissolution. One is when Brahma goes to sleep, and another is when Brahma dies. When Brahma goes to sleep, the highest planetary system does not dissolve, the lower planetary systems, beginning from heavenly planets downwards, everything is dissolved. And when the day comes out, they are again created. When the living entities enter into Brahma, or into the Body of Narayan, they keep their own spiritual body, that is very small, 1/10,000 of tip of hair, and when there is again material creation, they manifest again with different kinds of body. Just like a man sleeps at home without any dress, and when he goes out to work, he dresses himself. So similarly in creation, there is different kinds of bodies for working, and whenever there is no creation they remain in their own spiritual body sleeping. No, there is no complete annihilation at the end of Kali yuga, there may be some disturbances, but not complete annihilation. There are thousands of Kali yugas in every day of Brahma, and they come and go just like seasonal changes.
For dishes, best thing is everyone who is eating Prasadam should wash his plate. Otherwise, one man has to do so many dishes. So even the guests should also wash their dishes, that is the system in the Temple; not leave one man to do it.
Milk and salt should never be mixed, it is improper, and will cause leprosy. But salt can be mixed with yogurt.