I always thought that you could simply set the engines to overload (or any one of the auxiliary reactors/power supplies), obviously by over riding all the safety protocols first anyway, even if the ship didn't have a dedicated auto destruct and the auto destruct just does this anyway AFAIK, via voice command through the computer.
AKA-Dean
"I will never make excuses for who I am. It is the way I was born. I am a HUNTER. a BONE COLLECTOR."
Wave Man, the term "wave man" is the English translation of 'Ronin' (Japanese word) and literately translates to "wandering person" and in a modern context a WaveMan is one who is socially adrift or a SalaryMan who is between employers.