The act of a player clearing waivers and being assigned off a 40-man roster to the minors, counts the same as an outright in regards to player rights.
Dany Jiménez, Nestor Cortes, Travis Bergen, and Logan Verrett are examples of recent players who were able to elect free agency after a single "outright", because they had been returned previously from the Rule 5 draft (which technically counted as their first outright).