As far as a switch for a rinse option,
Tim in Maine is right about the Bendix Economat (with the Rinsaver dial to reduce the number of rinses from two to one) being the first machine to have a switch to give rinsing options. With the poorer extraction, many users and even the designers of the Bendix Economat felt two deep rinses were necessary since it extracted less effectively than a wringer and two deep rinses were the minimum & standard number of rinses for a load washed in a wringer washer. To save water however, since the Economat had to rinse with warm because of the rubber tub and to make the textiles as relaxed as possible for optimum squeezing action, in cases where the hot water supply did not allow for two rinses, Bexdix allowed the user to opt out of the default second rinse. Yes, this is sort of the opposite answer to what you were expecting, but in a backwards logic kind of way, it could be correct.