Deborah at Teach Preschool made some dot dabbers (also called bingo dots) for her school. I have always loved these and bought a colored set of washable ones at the local teacher store. They are very expensive, and when one child tries to use it like a paint brush, the little sponge comes off. They have non washable ones at the Dollar Tree, but that can get you into some trouble. I have seen refillable ones at the teacher store but never bought them. Deborah says they didn't work out the way she wanted, so she made her own. You can see them here.
As I was looking through my cabinet, I saw this bottle of formula which I am not using because I am breast feeding. They are the premade ready to use by just putting on the nipple. I'm not sure if they sell them like this or if they just give them away at the hospital. But they looked perfect. And many people use formula, and if you know someone that works at the hospital, I think this is what they use.