XANGNIER Water Bottle Cleaner Brush Set#XANGNIER#WaterBottleCleaner#BottleBrush#StrawBrush#CleaningBrush

Straw Cleaner Brush Set, 10 Pieces 10 Inch Stainless Steel Handle Straw Brush Set, Extra Long Straw Brush for Tumbler, Sippy Cup, Water Bottle and Tubes#strawcleaner#strawbrush#strawbrushset#tumblerbrush#sippycupbrush

2 Pack Straw Cleaner Brush, Reusable Metal Handles Straw Cleaner Brush Extra Long for Stanley Mug 40, 30, 20 oz, 10mm Wide Straw Cleaner Brush for Sippy Cup, Water Bottle and Tubes (Clear+Clear)#strawcleaner#strawbrush#Stanleymug#sippycup#waterbottle

Have you tried to use a strawbrush, they come in real handy when you need them, also try soaking it baking soda and vinegar then wash it out with dish soap.