Reusing 25L containers from car wash? Good or Bad

[BristolJoe]

Hi everyone. Just looking to get started up with a backpack system and noticed my local car wash had a bunch of empty 25L containers lying about. Managed to get 10 off him for free but they previously contained hydrochloric acid 36%.

Is it safe to reuse and store pure water in them and if so how would you clean them?

 

[Dave B]

Rinse them out a couple of times then fill completely and empty again
Then safe for pure
I’ve always done this

 

[Shinyboy]

Give them a good rinse and your be fine