100% false. First bonafide infomercial aired in 1949 for the vitamix and it was 27 minutes long. Harrington was born in 1956, 7 years later.
Vitamix posted it on youtube over 6 years ago as historical archive. Here is a link, so you can verify the entire 27 minutes...
And a youtube comment from his grandkid...
Furthermore, not only was he not the inventor of the infomercial of which he claims. He also claims to have pioneered the brand of as seen on TV products. Ron Popeil and Philip Kives were knee deep in as seen on TV products before that imposter was out of diapers...
Here is 3 1/2 minutes of what is probably 5 minute chopomatic infomercial because they cut the "here's how to order" portion off the youtube video...