The definition for leaching is almost identical: to part with soluble constituents by percolation (kind of like we do with coffee).

The root of lixiviate is 'lye'. Water was passed through wood ashes and the resulting constituent part removed was lye. While it is a caustic substance on its own, lye is used in the making of soap. Something unwanted is found useful.

If we look at McDonaldization as a hot liquid percolating over our culture, what is ultimately removed by this process is that which we generally recognize as 'culture'.

I'm not quite comfortable calling McDonald's a culture, although in a technical sense I suppose it is. For the sake of argument, it isn't.

While the other words associated with lixiviate seem to carry the conotation that the removal of something negative, the end result is something useful. With a literary or imaginative twist, if those traits that indicate a culture are lixiviated, what is removed can perhaps be seen as a negative of the homogenizing force.

In this case, would it lixiviate it, market it and ultimately homogenize it?

In this case the lixiviation process is attempting to squeeze out those parts that are marketable. Instead of lye, what is extrapolated would be things identifiable as 'cultural' or 'subcultural' or 'countercultural'.

Even Woodstock had corporate backers. It would not be long after Woodstock that tie-dyed t-shirts were sold in department stores. Hippy culture lixiviated.

We squeeze out the culture and are left with a shell of something that once was deemed to have had substance. What is left is imitation.