How do you clean out an old, OLD bottle for crafting projects?

Fill it up with vinegar and let it sit for a few days. Some like denture cleaner tablets.

Pour the bottle about 1/3 full of white vinegar, then add rice. Swirl and shake shake shake! You can also use fine grain sand. Repeat as needed

Be aware that vinegar may etch the glass . I'd go with the denture cleaning tablets .

Depending on what is inside them but I have found that if you add rice and or course salt with Dawn, they come clean.

A long thin brush meant for baby bottle cleaning works well.

Fill with clorox and let it sit a spell.

Thank you! Great ideas and suggestions! I am going to start with rice and vinegar.

Denture cleaning tablets.

A baby bottle brush and Dawn.