I want our softball team to use fewer disposable bottles, but my proposed ban backfired. What would work better?

After our softball fixture, I picked up a bag of empty bottles beside the bench and posted, "Reusable bottles only from next week." I'm not captain. I'd been angry about the litter and wrote it as though I could change the team's arrangements.

A player who comes straight from work said she sometimes buys water on the way. Another asked where she would refill a bottle at that ground. I hadn't checked. Both also said they take their rubbish away, so the message felt directed at them for a mess they hadn't left.

I still want less waste around our fixtures. I also owe them a correction to the way I announced it.

How would you move from my attempted rule to something the team might actually choose? I'm prepared to help, but I don't want the answer to become buying twenty bottles and discovering that storage, washing, and remembering them are now another job nobody wanted.