I think getting them use to drinking from the bucket at home helps (we take the same bucket to the show), the other thing is letting the bucket set, the chlorine will go away, we fill buckets for the morning the night before, fill the buckets for later in the day in the morning. If you have several calves, the tubs The red round tubs with rope handles) that hold about 20 gallons are good to have and keep filled, some calves will drink better with a larger tub then they will out of a bucket. Again we would dump and refill in the late evening and use them to water in the morning. Refresh is always a good product to add.