What is the best way to clean vintage bottles?

I had some antique oil and vinegar cruets that someone gave me. I couldn't get them to look that great so finally, I used white vinegar with some liquid dishwasher detergent (I found a small bottle at the Dollar Store) and hot water. I let that sit for quite a while. It really did the trick. Maybe that can help you too.

I was going to suggest baking soda and white vinegar. I don't know that it'll actually clean out the residue, but it'll be fun to watch and it can't hurt. ;-) Good luck to you.

Put some dry rice in the bottle and shake it.

I've had success with denture cleaning tablets like Efferdent. Just fill the bottle with water and drop a half tablet in. After doing this a few times you will get to know how much tablet you will need.

Try Barkeepers friend or soak in oxakic acid solution , the main ingredient

Does anyone know how to get smoke stains out of xstitch without ruining the thread colors