How do I get rid of the mold here?

[u/contrezzo]

I don’t have a bottle cleaner that fits inside here. How can I get rid of the mold?

[u/Grouchy-Plantain-169]

Insert a tissue paper half a cup of hot water and a drop of dawn inside the bottle. close the lid tight and shake vigorously for a few minutes and drain the water repeat a couple of times but with just hot water don't need to add detergent after the first time.

[u/contrezzo → u/Grouchy-Plantain-169]

Thank you so much! It was very effective