Programmers Hold Funerals for Old Code
Theoretically what you described possible, but your IP address would get banned pretty fast for querying the frontpage every ten seconds.
Slashcode works that way.
There's no need to do that, either.
Statistically, you ought to get FP once in a while if check back at random intervals (not every topic though), since the script would write a comment faster than a human anyway.