I don't think it takes imploring to get someone to be your accomplice in 'disappearing' a child. I have in mind Venus Stewart's case, where her husband asked a young guy to help him in her abduction and murder by acting as an impersonator for her husband so he would have an alibi. The testimony of the impersonator was chilling. He was very matter of fact and entirely devoid of emotion when relating the details of the abduction and murder, with Venus' husband calling him on the phone, giving him a blow by blow.
When describing how her husband asked him to participate, well, he had also described them going to Wendy's for burgers, and to Busch Gardens, and there just was no difference in his tone or more importantly, his language. It just was no big deal. It's hard, listening to it, to wrap one's head around the fact that it is murder being discussed and described.
I think to get someone to be your accomplice, it simply takes a recognition that something is amiss in the personality of the potential accomplice. Something 'twisted' maybe, or simply not there - a lack of caring for others. I don't know.
The relationship between Venus' husband and this young man seemed to be a strange one. There seemed to be some unusual emotional need, each for the other, and I am not implying any sort of sexual undertones to it. It was, to all reports, just a friendship. But there seemed to be an unusual dependency or need. I can't quite put my finger on it.
This unusual dependency or need, I think is may be the key thing that would have existed between Terri and an accomplice, if she was involved in Kyron's disappearance, and did have an accomplice.