Yes. Two polarizers can act as a variable ND: rotate them relative to each other and transmission changes from roughly one polarizer’s normal loss (about 1.5–2 stops) to very dark. In practice, this is essentially how variable ND filters work.

Drawbacks versus a true ND filter:

• Polarizer effects remain. They reduce reflections and can darken skies, which an ND filter does not do.
• Color shifts can appear, especially near maximum attenuation (for example yellow or purple casts).
• More glass/air surfaces can increase flare and reduce contrast.
• Stacking filters can cause vignetting, especially on wide lenses.
• Very wide-angle lenses can show uneven darkening because light hits the filters at different angles.
• Two polarizers may cost more than a single ND filter.

Compatibility note: the light must remain polarized between the two filters. A front linear polarizer works, or a circular polarizer mounted reversed; if you need autofocus, the rear filter should be a circular polarizer.

So: yes, it works, but a dedicated ND is usually preferable when you want neutral, even light reduction without the side effects of polarization.