Jobs at small Tulsa companies nobody posts about, sales associate here

Two small Tulsa employers told me they are hiring but have not posted yet. Any experience at all would help. One is a print shop, one is an accounting firm and one is a clinic. Should I visit in person?

Visiting in person worked for a trades job. For office jobs, email was better.

A short email with two sentences about what you can do and your résumé attached worked for me. I followed up after a week.