Anyone ever go to one of those tax-reduction services?

[Flaxbee]

A good family friend has asked me for advice in dealing with state and fed tax officials; this guy needs some major help. He's in his 70s, working with a good income, but never ever really paid much attention to his taxes (he earned beaucoup bucks years ago, never paid taxes, had his house seized & auctioned, etc.) and needs someone to help him negotiate a settlement so the tax authorities don't make his life hell now that he's started to work again. These friends always come to me b/c I'm a lawyer, but I have to explain that I can't do that kind of law in a state where I no longer practice or reside, and frankly, I know zilch about current tax laws.

Has anyone had any experience, or knows someone who has, with this kind of third party tax negotiator? I know there are some reputable not for profits out there, but there are also a lot of freelancers who are scammers.

Help!