Normally the process requires inserting robot.txt and such before requesting the removal. However I have parked this domain, which is no longer linked to any sites. However, when I typed in the URL it still shows up, even after parking it for 3 weeks. What is the best and efficient way to get it dropped completely from Google's index?
The worst part is most websites indexed as parked page will have a rarely visited by Googlebots. You need some authority link, not high PR but high aged pointing to your homepage letting Googlebots acknowledge the changed first.
Before parking the domain you could have used the index removal tool from Google's webmaster tools. Note: You have to disallow: / in your robots.txt file Good luck.