pretty sure it is bottle drop with a collection of replacements just after. you tell (shout out?) to the marshalls what you want before you get there and they hand it to you. if you use a speedfill then i guess you might need to spend a few secs transferring the new liquid into it (dunno, don't use a speedfill).
bento box or gel-filled bottle for other provisions. don't know about chall henley, but i'd assume it is similar to im in that the aid stations have bars (possibly gels, too) that you can pick up to save you carrying 20 of them in your jersey.
that's my guess, a grown up who has done it can tell you for sure.