How do you make Firefox 12.0 Beta 4 browser run off Comodo's DNS connection?

Is it possible to make Firefox 12.0 Beta 4 browser run off Comodo DNS (Domain Name Server) connection?

If so then how?

Currently, I have my Dragon Browser set to run off Comodo’s DNS. I’m also running other software on my laptop off Comodo’s DNS connection. This was a new option while installing Dragon Browser version

As a result of this option, is Firefox 12 Beta 4 then running off Comodo’s DNS?

As for performance, Firefox 12 Beta 4 browser runs slower than Dragon Browser

Hi pressrelease,
Please choose your operating system on this page and follow the instructions to make Comodo Secure DNS active system wide.