Question on using two polarizers has vari ND

[nemesis256]

I've read a while ago that you can use a linear polarizer on top of a circular polarizer as a variable neutral density filter. But my question is, will this increase the polarization effect or will it simply reduced the amount of light coming in? So let's say a circular polarizer cuts the reflection on glass by 80%, and then with the linear polarizer, will it remove even more reflections or only reduce the amount of light? Another example is, will it make a blue sky unrealistically blue?

[nemesis256]

Well I got a new circular polarizer (I needed a new size for my new lens) and I tested out using my two polarizers as a variable neutral density filter (the second one was reversed). It wasn't as great as I was expecting. it was extremely sensitive, and at a certain point this nasty blue tint appeared. If I made the image dark enough, it was so blue that it would not be recoverable in post. It would be very hard to remember at which point the image is too blue. So I've decided to stick with one polarizer and plain neutral density filters on top.

Does anyone actually use this method (one circular and one linear polarizer) for making a variable neutral density filter? Have you experienced the blue tint? Do you have a way around it?