If they are still have really watery poop, I would just give them plain tap water and their feed for a few days until you see some firmness return. From what I've observed from my own, chickens will generally lay poops in a pattern like this:
#1 fairly firm, some brown and white (dries into a cute little turd..lol)
#2 semi-firm, mostly brown
#3 brown, sorta watery, slightly stronger smell
#4 eeeww, really smelly, sticky and liquidy (in our house we call these the Poo-Bombs! They dont really dry, they just kinda 'smear' when you try to clean them up...lol And they smell AWFUL!
)
And then repeating back at #1 throughout the day. Maybe you are just noticing the #3 and #4 poops
Or...chances are more likely you may have slightly overindulged their little tummies with tasty tidbits.
I'd hold back all treats and water additives until they 'firm up' and then try just offering one thing at a time, maybe spacing them a day apart. Think of it like moving a new baby to baby foods; you try one at a time and watch for reactions before moving to something new.
I hope I've been somewhat helpful! Good luck with them poobutts...They only get smellier! lol