Subtle, but perhaps too much so. Why not go for the more aggressive approach of slapping “TRIAL EXPIRED - GENERATED BY AN UNLICENSED COPY OF website.com” across all pages, images, invoices, and so on? A faded out website looks broken, a website indicating the owner’s questionable business reliability much less so. Especially when it comes up in documents hitting other people’s accountants!
Modern security enhancements to browsers make iframeing random websites a lot more difficult than it used to be. You’d need to mirror the video, but that would take away some of the old internet magic.