I have a 5 gallon bucket that I used for waste water when doing water changes. The other day I used that bucket for cleaning a pair of shoes in which laundry detergent was poured into the bucket. I rinsed the bucket out multiple times and even left it over night filled to the top with a generous amount of water conditioner in it. After that I filled it up in the sink with water and let the water over flow for a few minutes. Finally I boiled water with and poured it in the bucket before dumping it all out. Would it be safe for Aquarium use or should I just buy another bucket.