I just obtained some used food-grade 55 gallon steel drums to use for rain barrels. They previously contained sunflower oil. I’m looking for suggestions on the best way to clean them out prior to water collection. I plan to use them strictly for watering the garden, not for drinking.
The guy I bought them from said he just pours a little hot water in them, seals the lid, and lets them sit overnight, which I guess steams them clean. Then he pours the water down the drain. Northern Colorado nights are cold this time of year, and I really don’t have room to bring them inside. Also, city municipal water And sewer departments frown on dumping any type of oil down the drain, as it congeals and can trap other waste materials, potentially clogging the sewer pipes.
Dishwashing detergents, such as Dawn will break down grease and oil, at least long enough to separate it from your dishes, but I’ve read that the oils can re-congeal later. It would be nice to be able to compost what I dump out, but I don’t want to add a lot of soap or oil to the pile. Small amounts of either seem to be tolerable, but I don’t want my compost to go anaerobic.
Are there any organic soaps (Dr. Bronner’s?) that will permanently break down vegetable oils to a compostable or flushable form, or is this too much to ask?
My less elegant idea is to clean it out with Dawn and minimal water pour it into a 5 gallon bucket lined with a kitchen sized trash bag, and leave it outside until the water evaporates. Then throw out the bag.
I welcome any other ideas.
Thanks,
Jeff