Try the liners anyway – even though the poo is liquidy it still peels off with the liner. if I remember correctly. The liners are the one thing that really made cloth diapering work for me! I had all breastfed babies so don’t know about the formula poo, but I think you should be seeing loose stool, gravy-like?, but not liquidy like watery. I know that my first was so tiny she didn’t fit into the cloth diapers at first, but with my second I bought a few in newborn size and used them right away – so I must have been successful with the liners. Funny how I don’t remember every detail anymore LOL.
It is worth a try to see if you can make it work – saves so much money! I have also heard of some kind of thing that attaches to the potty and hoses the diaper off into the toilet? Some other moms here might know about that.