Q. What's the best way to avoid having to go through the slush pile?

A. There isn't one. You can't avoid the slush pile. Every route to getting published by a real publishing house passes through at least one gate where an agent or editor has to evaluate your book and decide whether to take you on. Sometimes you go through several gates like that. All those agents and editors have too much work to do and not enough time to read, so they've accumulated a stack of unread submissions. That stack is a slush pile.

Very occasionally, a new author will dodge the slushpile. It's not usually anything he or she planned to do. It just happened. If you try to do the same thing, it won't work.