"POO-sh" in place of 'push' is from eastern Ohio. Just like "BOO-sh" in place of 'bush'. Actually, saying it's an "Eastern Ohio" pronunciation is a euphamism for saying it's Appalachian-hill-jack-ignorant.
Sorry, this topic isn't dead yet. "Poosh" and "boosh" are not spoken in eastern-most Ohio, where the "hill-jacks" are, but rather in the area the includes Columbus and central-most Ohio and extends somewhat toward the southeastern "hill jack" area. It is therefore not a "hill jack" phenomenon but simply a Buckeye speech/use pattern (along with the nasalish vowels of Cleveland and the use of "Please?" when meaning "I beg your pardon?" in Cincinnati). And (please!), don't assume that being from rural Ohio makes one ignorant, hill jack or not. Bryan Son of Ohio/Kentucky Hill-Jacks
