I'm always giving Gus old clothes (etc.) for bedding that smell like me. He likes to smell me, and then, when he uses it as bedding, it smells like "us." (He accepts me as a really big rat, I think, and this is the next best thing to me being able to go into his igloo and sleep next to him.) I think your babies will love the jeans...they smell like you, they are soft, you can dig in them, and you can even chew them! To make it interesting, you can always hide some "sweeties" in there, too.
IN ORDER TO MAKE SOMETHING SMELL LIKE YOU, BEFORE GIVING IT TO YOUR RAT: put the item, or a cut up piece of the item, inside your pillowcase. You will sleep with it every night, and it will take on your scent faster than you think.