Thats a diferent type of knowledge, she was wise, she didnt have that big of knowledge when it came to the world around her. And in Sasori`s case it would still be difficult to survive such a process. And even tough Chiyo knows how to seal her puppets on scrolls, thats a different type of Fuuinjutsu, Itd be like saying that Tenten can seal Bijuu inside someone just because she can seal a kunai in a scroll. You cant use the same jutsu on creating a Jinchuriki than using a jutsu to seal something in a scroll. Just look at Naruto`s seal formule: It's made with two four element seals; one seal is to contain the Bijuu and the other seal leaks out the bijuus chakra and mixes with the Jin's chakra. Does that look like a seal youd use to seal a puppet on a scroll?Chiyo would have know that simple fact if she was an uzumaki cause chiyo has knowledge and information from every village she has great ties and informants if you remember that episode when Baki went to them for help knowing sealing weak argument most skilled level ninja knows at least one sealing jutsu she was in the puppet master core they seal puppets in scrolls so it is much easier to carry... Now how sasori survive turning himself in a puppet not much is know of this but if you remember kabuto was working for him and kabuto is a skilled medical ninja sasori used mind control on his subboradenets to have them do his bidding who is to tell that it was not done by kabuto so the life force thing kinda blow up there