I'm assuming you're talking about the fuel system flush by Motorvac. A lot of shops offer the service, or a similar one with another brand name. Once they buy a flush machine, they can buy the chemicals from anywhere, and most Denver area shops use BG, which is an awesome product. CARQUEST sells the Motorvac machines, and the chemicals that go with them, but they're a parts store so they don't actually perform the service.
The machine forces extremely aggressive cleaner/solvent through your fuel system continuously, cleaning your entire system. The stuff is so aggressive that if you just put it into your tank it would eat all the varnish off its interior and clog your whole system. Regardless, you should change your fuel filter after the flush.
Unfortunately I can't recommend a particular shop that does this, but if you ask around, you'll easily find one anywhere.
If you're interested in fuel system treatment, try out the BG 44K product first...this one you just put in your tank. It's incredible...you WILL feel a difference during and after using it. It's another product by BG, available at most parts stores. Costs about $22 a can though.
Mr.Clean '03 Taco
Aren't you a Regional Manager AND a little bitch?
As yet unnamed '03 Honda Shadow Sabre 1100