I'd be interested to see the post in question, so that I or others can tailor a more specific answer for you. In the meantime, while my area of focus in Naval history is during a point in history where this wasn't really an issue (WWI/Interwar period/WWII) for most sailors, I did study quite a bit of earlier naval history and tradition, so I'll give you general overview.

Keep in mind that sailing like many other occupations and traditions throughout history, was keen on keeping women (in a professional capacity) out of it for a variety of reasons. This was usually justified with rather flimsy (by today's standards) logic, with ideas like "Women are emotionally weaker then men, can't handle the rigors of sea life, they'll just distract the men, sex, etc". This mindset typically resulted in traditions and superstitions forming from within the sailing community that helped "cement" the argument that women would only cause trouble if they were aboard a ship while at sea. One of these superstitions, was that having women aboard invited poor sailing conditions and storms, and that the best way to avoid such weather, was to just keep women off your ship all together if it could be avoided.

Now, as far as the idea that women were actually being thrown off of ships due to bad luck, Suzane Stark's Female Tars, cites a specific example of women being thrown overboard during the final voyage of John FitzAlan, First Baron Arundel in 1379. During the voyage, he had his crew throw a group of nuns that they had kidnapped (and raped earlier while taking shelter in their nunnery) from Cornwall overboard in order to survive a storm they encountered while en route to Brittany. This is usually the example I see presented as 'proof' that women were commonly thrown overboard to end or avoid a run of bad luck.

The problem with Stark's argument is that she frames it in such a way that makes it sound like Arundel gave the order to cast the nuns overboard specifically out of the superstitious belief that it would appease the storm and save his fleet somehow. Which for obvious reasons, both in the contemporary and past, is ridiculous. It also requires a very narrow reading of Thomas Walsingham's (a Benedictine Monk and chronicler from the late 14th century) works.

The most likely reason (at least how it's been agreed upon by myself and others I've studied this particular case with), was that the ships at the time were weighed down by the extra provisions and "passengers" Arundel's men had taken on board with them after they left Cornwall. In an effort to lighten the load, keep the ships upright and sailing despite the constant waves crashing on deck, the order was given to dump unnecessary cargo that was weighing the ships down. That unfortunately included the kidnapped group of nuns taken by Arundel's men mentioned earlier. So obviously, because this event has the elements of the superstition packed into it (women thrown overboard due to rough seas or "bad luck"), it's taken for the face value rather than the pragmatic and more common reasons as to why captains during that era, often jettisoned cargo (and sometimes people) to alleviate conditions that were hampering their ability to sail/continue a voyage. The only difference was in this case, Arundel's men cast around 60 nuns as well as cargo overboard (which was an issue entirely by itself later on during the height of the African Slave Trade), and for obvious reasons, this get's peoples attention.

Now that's just one example that I know of, and it's certainly possible that it has occurred elsewhere specifically due to the superstitious belief. However, from everything I've ever read on the subject (Naval History/Tradition, primarily from the Age of Sail and onward), it wasn't an issue that came up all that much (except with Slavers, and for a completely different set of reasons) and that the superstition usually went nowhere further than idle talk by some ordinary seamen.