What’s your favorite piece of Adeptus Mechanicus silliness?

They have a whole ritual for pushing the start button.

From Dark Heresy: The Latheworlds.

TALENT: RITE OF IGNITION

The Adeptus Mechanicus has many rites and rituals associated with coaxing machine spirits to life, so many, in fact, that knowing all of them would be quite impossible. Lathesmasters tend to be more practical than their Tech-Priest masters, and often there are tense conditions when it is not always practical to chant a three hundred line Canticle of Initiation. Most have their own, self-taught "rite of ignition," a form of prayer to the machine-spirit that involves striking the object in question several times, usually with sufficient force for activation. They tend not to enact this rite in the presence of Tech-Priests, as many would consider it heresy, but few can argue with its effectiveness.

-Mint Linux Guy