Great question. Due diligence is essential when seeking alternative methods. I don't have a direct answer to your question. However, my suggestion would be to create your own provider selection criteria that includes , travel costs and provider credibility. Since you'll need to travel, try to select a city that has multiple providers with some sort of track record. I would then call the office of each provider and ask for credentials pertaining to prolotherapy, and eliminate any provider without accredited training. I wouldn't let anyone stick a needle in my neck who wasn't directly trained on the exact method. Fortunately prolotherapy and other deep needling techniques are fairly common, so creating your own selection process shouldn't require too much re-inventing of the wheel.

Hope this helps your cause.

Hains