Managed to feed the stuff to Kaylee an hour ago. She's alternating between muttering "shutupshutupshutup" and vomiting at the moment. Not sure if that's a good sign, but other than that she's pretty docile. We've freed one of her hands so she can grab the provided bucket instead of throwing up on the carpet. She was lucid for about five minutes a little while ago, so I made a transcript of our conversation which can be found below.
Kaylee: shut up shut up shut up shut up shut up
*Chester and I stop talking and look at her*
K: No, keep talking.
C: Then who needs to shut up?
K: ...*attempts to cover her face*
V: *wary* He isn't going to suddenly walk in here, is he?
K: Nooooooooo...think. Hasn't shown any sign of wanting to come here. Might send Indoctrinated. Probably not.
C: Why not?
K: Not many here. Not many here fighting, either. Have seen no other Indoctrinated.
V: We've had run ins. There are proxies here.
C: You called them Indoctrinated. We called them Proxies, Hallowed, Agents, Maskies...
K: Have many names.
V: Is it still talking?
K: Wants, obey. Compulsion.
C: It compels you to do stuff?
K: Almost...not obey. Want the same as. Don't know.
V: Kaylee, is there a particular reason why you are having trouble using pronouns? We can't understand you
V: Pronouns. She, he, it, you.
K: *startled* Am using!
C: If you are, we can't hear them.
K: *opens and shuts her mouth as if attempting to speak, coughs* Strange. Assured is not intentional. Stuff tastes weird. Water?
(insert pause while I go and get her a glass of water)
K: Thanks. *drinks half the glass* What is stuff?
C: Dunno. Friend of ours called Jeff sent it to us, apparently it cures Hallowed-ness or at least breaks It's grip on you. I guess it works since you've stopped trying to kill us both, although hopefully the speech impediment won't last.
(Kaylee throws the remaining contents of the glass of water at Chester.)
V: Is It still trying to compel you?
(she falls silent after this and refuses to speak)
Any theories on what she meant by "Compulsion" and "Want the same as"? Or indeed why she is unable to use pronouns? Jeff, you were the one who supplied this stuff to us, any advice on why she is unable to use pronouns or the fact that her vomit looks like she's been eating charcoal?