1. what the heck makes you think the infection IS removable? A complete format and reinstall may be needed. Most end-users (90% or more) can't do this and or can't afford to pay to have it done easily.
2. how would the ISP verify that anything had been removed if there's no network connection? I'm certainly not letting the ISP scan my boot drive.
3. There is no good solution, "computer security" when applied to clueless home users is an oxymoron, and we may be permanently fuched as far as having an open secure and private internet goes, primarily due to government's unwillingness to actually go after the perps. because it's "hard" and YET - we're spoon fed stories that IF true, would lead one to expect that their capabilities would make it relatively easy for them to locate bot-net operators.