How do you wash your boston rounds?

I like to wash my new boston rounds before I decant my nic base into them, no telling what's i there from the factory.

But because of the narrow mouth, I wash them by merely violently shaking them with with lightly soapy hot water inside the bottle and then rinse them really well with hot, hot water.

But it would be nice to actually be able to scrub them on the inside.

How to you all clean yours?

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