Painting the bucket black would be helpful. Sun would give it a little heat.
There is some merit to it, but wont steer a frost too hard.
I got a young orchard, kinda want the buds to not make it a few years to get some tree size.
Plan at home is to plug in a few electric fans overnight in the backyard. Sprikling water on trees has been done succesfully.
The ochard down the road from me is being bulldozed. They have like 100 of those orchard heaters just rotting by the road. The tree guy and the gearhead in me wants a few to play with.