55 Gallon Drums for water storage

I want to get a 55 gallon drum or two to store RODI water in so that its ready for when I have to mix water. I can get them free at a car dealership but they have had windshield washer fluid in them, and the other place is a car wash, that had soap in them. Can these be cleaned so that they are usable or do i need to look for something else.



Looking for your thoughts.



Thanks,

Chad.