Schwa insertion into the bi-consonantal onset for emphasis?

I want to know if American English speakers have regional differences in inserting the schwa between initial consonants of words such as great, crazy, professional, and crash for emphasis. For a case in point, Americans that are born and raised in Maryland do not insert the schwa for emphasis whereas Americans that are born and raised in Los Angeles CA and Texas do insert the schwa for that purpose in the plosive and liquid clusters.

E.g. (1) Gareat! /gə'ret/
and (2) Carazy! /kə'rezi/

Here's my take: the schwa is inserted into words that begin (as tchrist already mentioned) with a stop and a glide. I've heard this insertion most often when someone is shouting a word, whether to be heard or for emphasis. It's a feature of over-the-top delivery, like what you'd hear from a carnival barker, a street vendor, a revival preacher. I've heard this in dialogue on TV shows and movies, and not necessarily in the context of regional diction.

In short: it's probably not regional, just contextual.