Grout vs. Caulk: When to Clean and When to Replace Moldy Materials

https://freshairhomes.silverstonebrief.com/posts/grout-vs.-caulk-when-to-clean-and-when-to-replace-moldy-materials

Mold on bathroom sealants is frustrating, but you can't treat grout and caulk the same way. Grout is porous and often needs scrubbing with bleach or even replacement if mold has seeped deep. Caulk, which is flexible silicone, usually just needs a clean wipe, but once it's cracked or persistently moldy, cutting it out and reapplying fresh caulk is the only real fix.