I have a couple stainless steel bottles. I only put water in them so there isn’t a need to do much more than rinse them out.

If you need to wash them, just use soap and water and a bottle brush, available at your local kitchen supply location (hardware store, Sur le Table, William Sonoma, Target). rinse it out well, then stand up side down on a towel to drain and dry..

Try this

@Kayak8 – rice with vinegar: great idea!

I boil a bag vinegar in my electric tea kettle from time to time to remove deposits. I might then pour some boiling vinegar into a stainless water-bottle and shake it. I don’t know if this is “proper” but it does remove the “white crust”.