I posted a similar topic on this not too long ago. My advice, call the state board and ask for specifics on your situation. Mine was very helpful and I called 3-4 times in a couple of weeks to clear things up. I am in same situation, private with no CPA in the company. She said I could use my old professor to review some of my work and sign off that I was performing accounting like services. I think the work experience requirement is more about ensuring CPA's keep up a reputable standard. Not really verifying your work is all correct but that you just have experience performing services. The board said I could also use a CPA working for our firm to review some work or even find a CPA in a local organization to review my work. The main thing you need to find is someone from the outside willing to help you out with this AND making sure your company will allow you to show someone from the outside your work. A CPA firm that works with your company would be ideal if they would be willing to sign off for you. I would definitely call your board though because as you mentioned, all boards are different.
Becker 2010, Missouri Candidate
FAR 96(4/26), AUD 95(5/28), REG (7/31), BEC (8/28)