How do I keep a toothbrush holder from getting moldy?

r/CleaningTips consensus is to pick a holder with a removable, dishwasher-safe base (bamboo dividers and stainless trays both qualify), rinse and dry brushes before storing, and run the holder through a hot sanitize dishwasher cycle every week or two. Sealed dust covers look hygienic but trap moisture against the bristles if the brush isn't fully dry.