Hi,
I remembered someone telling me about how vinyl used for incontinence or baby plastic pants is sometimes treated with lanolin in order to make it more skin friendly, softer or whatever the case might be. I don't know if it's true because of the adverse effect that oil has on vinyl.
However, I vaguely remember once having seen an advertisement for vinyl diaper covers using this as a selling point.
I googled for it and could not find anything about this use of lanolin, though I did find something completely different that I wanted to ask about. My searching for "vinyl" or "plastic" and "lanolin" produced an avalanche of websites that oppose the use of plastic pants but favour using "woolen soakers" by way of diaper covering for babies:
"Plastic Pants, No! Woolen Soakers,Yes!"
I understand that this is not an "Average Joe" point of view but more - ehm, would "Alternative West-Coast-ish" cover it? - but of course it could be an interesting thing to research if it's any good.
But even though lanolin is essentially used (by sheep) to waterproof wool I have serious trouble believing that it would work in such a way that it could function as a diaper cover - at least a diaper cover that does something other than, well, exist. I can imagine that you can treat wool in such a way that it will repel a liquid that falls on it - in the same way that a sheep uses it when being out on a rainy day. The wool fibers, a bit waxy from the lanolin, will not absorb the liquid but let it slide down alongside the sheep, towards the ground.
But surely it won't work like that in a diaper cover .. I mean, if that would work, than a turned-over thatched straw roof would make a fine organic swimming pool.
Other than that, it's a bit over-the-top in how they put things like "plastic pants cause rashes" which I think is about as true as saying that the weather forecast causes the sun to shine. It sounds a bit like the automatic association train to me that goes like:
plastic -> unnatural -> BAD vs. wool -> natural -> GOOD

-m