I and many others have been critical of Usana Health Sciences (NASDAQ: USNA) for a while now. Fraud fighter Barry Minkow has argued quite compellingly that the company's business model amounts to little more than a cleverly disguised pyramid scheme. How did he figure that out? He read the company's filings with the SEC.

Since Minkow's report, the stock has taken a beating: an auditor resigned, numerous credentials flaps were uncovered, the SEC opened (and closed, sadly) an investigation, and the company has repeatedly failed to meet the growth expectations of the Street.

Now founder Myron Wentz -- who owns half the stock through Gull Holdings -- is offering to take the company private at $26 per share. His reasoning? In the press release announcing the offer, Wentz explained, "Going private will provide significant cost savings and will allow USANA's talented management team, employees, and Associates to focus solely on providing industry-leading products and building USANA's strong Associate network without the pressures and distractions brought on by the public market."

Exactly! Going private will allow the company to operate its shady business model free from scrutiny. The selling of overpriced vitamins based on the promise of the potential to earn a six-figure income working from home has earned a lot of money for Usana. But having to disclose the business model in black and white has attracted the scorn of critics.

Now Usana can go back to what it does best: luring people in to a multi-level marketing business without having to disclose as much information about what a rip-off it is.

But before shareholders get too excited, they might want to take a look at Wentz's history of offering to buy the company. Back in 2002, Wentz made a similar offer (for a lot less money), but then Wentz later announced, "To allow our shareholders to benefit from any increased value, I have decided to terminate my current effort to acquire USANA's operating assets on the terms previously announced."

What a swell guy! This is starting to remind me of the whole Parlux (NASDAQ: PARL) buyout that never was fiasco.

The New York Post reported today that Usana Health Sciences (NASDAQ: USNA) CFO Gil Fuller doesn't really have a CPA; he just says he has one in SEC filings. This is perhaps the most serious in a series of credentials flaps for Usana that I've listed on BloggingStocks last week. Here's the updated list:

• Denis Waitley, a director at the company, decided not to stand for re-election after investigator Barry Minkow uncovered that the PhD listed in his biography came from a long-defunct diploma mill. He also does not possess a Master's degree, although one was reported in numerous SEC filings.
• Dr. Timothy Wood, Vice President of Research and Development at the company, claimed to have a PhD in biology, but it's actually in forestry, which seems less relevant at a company that makes nutritional supplements.
• Myron Wentz, the company's founder and Chairman, renounced his U.S. citizenship to "move" to the tax haven of Liechtenstein.
• And now, according to the Wall Street Journal, Dr. Ladd McNamara has left the company's medical advisory board after it was discovered that he no longer has a medical license [subscription required]. A Usana spokesman said that McNamara surrendered his license in Georgia in 2004 in response to allegations that he improperly prescribed medication to a family member. He also agreed to a lifetime ban from practicing medicine in Ohio.
• CFO Gil Fuller claims to be a Certified Public Accountant. While it's quite common to let a CPA license lapse, he hasn't been one since 1986. Back then, people were terrified of communism, everyone in Boston hated Bill Buckner and the New Kids on the Block were cool -- OK, no, they weren't. But the point is that being a CPA in 1986 doesn't really mean anything in 2007.

In a few weeks, Usana will be releasing its quarterly earnings. You have to ask yourself: Given that the company 's management can't seem to stop lying about their credentials, why should we believe the earnings numbers they present, or anything else they say?