Well, there are programs where the IRS can reduce the amount owed, but only because of uncertainty (on the part of the IRS) of the accuracy of their version of the return or the ability to collect.
Some lawyers are better at negotiating with the IRS than others, but there is no reason to believe that the ones who advertise are better than the ones that do not.
The most common reduction program is called OIC (Offer In Compromise). You can file the forms without expert help, and, unless there's a complicated situation, you might do almost as well as a lawyer.
I'm afraid I might not be the best expert to answer this, but I'm not sure what the qualifications of such an expert would be, other than not advertising on television.