One third of the way through the cycle, shake all bottles vigorously.
Yes, it works with lemon-lime sodas.
Im not a scientist, but I can tell you Ive kept these for about a month with no problem.
(Or get four bottles and an empty, to allow room for the skittles.) If you want to make it more quickly, cut the skittles in half before putting them into vodka.
Everything tasted just like it always does and no one got ill.