BoogerWillie was designed to spare you the awkward moments when you can’t remember someone’s proper name when you need to address him.
There are alternatives, and probably regional variations, as well.
The more traditional usage would be “Sir?”, “Ahem!”, “Hey, You!”, “Excuse me?” or “Dude!”
None of these terms has the panache of “BoogerWillie”. The only term I have ever heard that came close was “BabyCakes!”, but that was a very specialized term.
In large families, there is a tendency to just go down the list of assigned names until the proper one is hit: “Dammit, BubRipSpaMurphy!” By learning “BoogerWillie”, and using it as an alternative, these embarrassing mis-steps can be avoided.
”BoogerWillie” is generally used only for males. The female form is “BoogerWilma.”