Right, so if I had to guess how such a person might change their mind, I would say they would have to go through four stages:
1. These anti-SBS people are evil sophists trying to help child abusers
2. These views of these anti-SBS people irrational; but they're not evil, just misguided and/or misled.
3. The views of these anti-SBS people are wrong, but they are actually reasonable views for someone to hold, given the evidence they have available to hem.
4. The views of these anti-SBS people are correct.
You're never going to jump from 1->4 directly; you need to start with going 1->2.
So if you're serious about it, then I guess I would start with actually trying to get face-time with some people. Look at the various people in this community, and find someone who seems either more reasonable, or more friendly / sociable: someone who is unlikely to turn down an invitation to coffee / lunch, and unlikely to hate a decent person right in front of them. If there's someone who's has a lot of influence, or is in the "core", that's best; but anyone within one or two steps of the "core" could be a good start.
My goals going into the meeting would be:
* Establish a human connection; see them as a person, help them see you as a person
* Make sure they feel heard and understood. Try to understand how they got into the work they're doing now; and not only the evidence they've seen, but also the personal experiences they've had. Try to mostly listen; and if possible repeat back to them what you've heard them say.
* Share your story, and some of the key stories you've seen or heard. If you can, stick to your observations and opinions; i.e., don't say "my nanny was innocent", but rather, "it didn't really seem possible that the nanny did it; it would have been really out of character" (and explain more about the nanny's character).
I'd call it by ear whether to ask "would you want to know if you were wrong" and "how would you know if you were wrong".
Remember the goal for the first meeting is to get them from 1 to 2: That maybe you're way off base and misguided, but that you're not evil. Getting to 3 would be a bonus if it goes well, but don't count on it; and there's no way 4 will happen over the course of lunch.
That's a lot of work, but you seem pretty motivated. Whatever you end up doing, good luck!