I’m often asked if there is something special that needs to be done to clean vases and buckets used for floral arrangements. And, the answer is YES. I like to use Clorox Clean Up for all my vases and buckets. I also use a toilet brush (only used for my buckets) and a dish washing brush (only used for my vases) to clean my vases.
You can also make a solution yourself of a watered down bleach. Just use bleach with a little water added to it. Rinse out the buckets and vases really well and let them dry naturally or dry them out with a towel or paper towel.