LionSage69
Member
He would've know about the advantages of shadow clones. I remember earlie in part two he used to speak to naruto and all of a sudden puffed to smoke making everyone realize he was a shadow clone and annoying naruto... But more to the point, in those conversations he would've been informed of things and known that he'd been told them after releasing the clone, like kakashis scissors paper rock experiment with naruto. I'm guessing that jiraya never used it to train naruto because he either didn't realise how he could take advantage of it in training or because it would've put a strain on naruto making him succeptable to being taken over by the nine-tails and he didn't have any means of suppressing its chackra