Fairly horrific stories of escaped crickets... back in the days before I realized the wonders of feeding supers to the adult dragons, I kept crickets. And they are vile, escaping little wretches, and excessively good at crawling up walls. And I, who will play with any non-venomous creature without a single issue, flee in absolute terror from insects and arachnids (this does include caterpillars, and worst, my phobia of centipedes). Try looking up and seeing a huge BUG on your ceiling while you're trying to fall asleep, and yes, crickets bite pretty bloody hard. And the bites itch like none other.
And there is always the one cricket that escapes... back in the days of my first adult beardie, and Oz managed to miss one cricket. That single cricket began singing out for his lost brethren sometime in the very early hours of the morning, and his cage was right next to my bed at that time, waking poor me from my sleep by making me think there were gongs going off in the dream I was having. Some amount of time of tossing and turning later, I hear one final "cheep", followed by a most satisfying crunching sound as Oz had a pre-breakfast snack.
And no, the vacuum idea really isn't cruelty, and it keeps from getting crickets everywhere and biting what they aren't supposed to bite. Insert some witty quote about wisdom and experience trumping youth, its late and I should be in bed, but hearken instead to the call of the crickets as the dawn rises...