Hi mate!
Actually, i dont see a problem with it. The reason why you dont see articles on the subject is probably because most people doing PU dont have a child (i dont know, but it seems logical).
In any case, how would you use your son? The only thing you can do with him is walk around the mall so you get opened yourself (as he is indeed a damn good conversation opener). the kid will love the walks, just be sane about it and make sure he doesnt catch some weird disease
. There is nothing wrong with doing that. Or perhaps i am a fucked up dude myself. However, and this is about the effect you try to reach, to be effective, it must not show that you use the kid to get in contact with women. If you prance around the mall and you open woman after woman, using the kid as a conversation opener, you will fail. It is not that you cannot open yourself, but it must seem like you dont have another choice. To women, it must seem like it happened spontaneous. Its the only way it will have a good effect.
Now back to the kid: it would be a bad thing if you put more effort in PU with the kid then you put effort in raising the kid. But i think you know that.
When women open you, talk, make some fun. Then say something like: hey, you seem like fun, how about a coffee later this week? Then we can get to know each other a bit better. That is how i would do it, but then explained very short
. One more thing: i think it would also be psychologically damaging if your son never sees you kissing a woman
hehehe. good luck mate!