But it sounds like this is exactly like those kludges.
Instead of detecting which browser the user has and saying "best viewed in X" where X is some other browser, how about detecting which features you need, and then giving a clear error on which were missing? This is better in many ways, for example if the next update to a browser adds the missing features to it, then it will just work on your site.
What would confuse them? You can customize the warning message to be as clear as you want. The benefit your users get is your page will actually work the second their browser can support it, not when you officially define browser X to be "acceptable".
What made it a problem in the past is that people would rely on weird, kludgy, non-standard behavior of Browser X and slap on a "Best viewed in X".