Have you give the Corid drench to the sickest? Try that with the other hen. Around .5 ml of undiluted Corid directly into the beak. Repeat once a day for three days.
I'm currently battling this in my flock. I've had three very sick hens that have gotten the drench along with the Corid water. I thought one was a gonner yesterday, but she's turned the corner today, her third day getting the drench. Remember this when you see coccidiosis symptoms. It often can save lives where the Corid water may work too slowly in heavy coccidia loads.
You will have the antibiotic covered once the med arrives, but I'm a believer in using an antibiotic along with Corid for any chickens showing symptoms as bacterial infection often sets in with coccidia eroding the intestines.