What you're proposing is unlikely to work in many environments. Even in the best of environments, where trust and respect course through every coworker interaction, people will still be looking to their coworkers (especially their superiors) to get a feel for how much vacation time is acceptable. In fact, companies with exceptionally strong cultures may be worse, as people really won't want to be a burden on their coworkers by taking more vacation days than average.

This is especially true for anyone with any sort of leadership role—whether it's an official senior position, a mentor, or just someone who is known for being a model employee. Your own behavior serves as a model for others, and no company policy is going to tell people any different.

I work for a small nonprofit organization with an extremely dedicated president. She's been very gracious with the freedom she allows her employees (though the official policies could be better), but I'm always wondering if she thinks that I'm actually working hard enough—not because of anything she's said, but because she puts in a ton of hours. I know many of my coworkers feel the same pressure.

If you're forced to take vacation time even when you don't need it, then try to find other pursuits—personal projects, reading, volunteering—that are still "work", but of the unpaid variety. Take the time to catch up with friends and family (especially if you have kids). Vacation doesn't just have to be about traveling and/or resting; it can also be an opportunity to catch up on other priorities.