If your that confused honestly id just have the parent supply the formula (read the back for directions, add the water first it should say that and never nuke a bottle) and have the parent provide the bottles as well and just send them home dirty at the end of the day, maybe rinse them out as a courtesy but just stick them in their bag and let them clean them. EVERY center i know of does this it isn't out of the ordinary.
I however provided bottles, i asked what kind of bottle they liked and got a bunch when they enrolled with the admission fee and they bought the formula because every child is different, there are so many kinds, id have the formula LEFT AT MY HOUSE so they never forgot it and the bottles were always there so i was never in a pinch. I soaked that all together at the end of the day and scrubbed them out with a bottle brush just to get the oily formula residue out then threw them in the dishwasher to sanitize and unloaded in the morning, easy peasy, just tedious . and i just ran the bottles under hot water in a large cup to warm them and tested them on my wrist, you could buy a bottle warmer, i never used mine.
toss the bottle after an hour is our policy here, don't save even in the fridge. a new bottle every time so you may need like 4-6 bottles a day depending on how much the child eats.
Good Luck!
