I'm here
The most immediate way I could see that happening is for your OC to swallow them, and basically, hide their signature under the magnetic field produced by his body, and then waiting for them to come back out the other end, or vomiting them up.
It'd be hard to sneak any sort of machinery in the prison though. Things like metal detectors are bound to be there.If robot won't work then it could be actual insects carrying small cameras, Im pretty sure she can create a devices to communicate with animals like its nothing
The most immediate way I could see that happening is for your OC to swallow them, and basically, hide their signature under the magnetic field produced by his body, and then waiting for them to come back out the other end, or vomiting them up.