I've made way too much dicer, err cider, and never had a sanitation problem.
I've never used a brush inside of my glass fermentation bottles, except for the initial cleaning of a couple of 40 year old 5 litre jugs I bought from the second hand store.
After fermentation, I fill them up with hot water, maybe let them soak for 2-3 minutes, and then empty them out. I don't cover them or anything, just put them on the shelf until the next use.
When I use them again, I mix up a rinse bucket full of sanitising solution and pour some in the glass vessels that I am about to use. Cover the hole with my hand, hold them upside down and shake them a few times. Then I rinse them with cold water, typically two fills and empties. Then I use them.
It's that simple, and after way more uses than I can count - never had an infection.
Edit: Didn't notice that this is in the beer section. For beer, I always ferment in a plastic bucket. When it comes time to wash, typically there is a thick ring of sediment at the top end of the bucket. I fill it with warm water and wash off the ring of junk with my fingers, nothing else because I don't want to scratch my bucket. Other than that, same as above.