Why ask why?  Try Bud Dry.
Don't be offended.  I just struggle to understand why anyone would want to overcomplicate something so uncomplicated as mixing warm water with some grain and draining it out.  But to each his own.  I don't care if a brewer chooses to fly sparge.  It's just that I've found cheaper and easier methods that work just as well.  That's all.
				
