I’ve wondered the same about hot water and bristles—haven’t seen mine actually warp, but I do feel like they get a bit “fluffier” faster if I rinse with really hot water. Maybe that’s just normal wear, though. I usually stick to cool or lukewarm now, just in case.
The musty smell is such a pain. Airing out the brush head and base separately makes a huge difference for me too, even if it feels a bit over the top. I once forgot for weeks and ended up with that gross pink gunk (probably bacteria or mold?) at the connection point. Not fun.
Humidity definitely seems to speed up everything getting funky—especially in summer when my bathroom turns into a sauna after showers. I try to swap brush heads every 2-3 months year-round, but sometimes I’ll switch sooner in July/August if it starts looking or smelling off. Maybe it’s just psychological, but it makes me feel better.
The forgetting-to-brush thing is real when you move the brush out of sight... I gave up and just keep it in the bathroom now, even if it means dealing with more moisture. Out of sight, out of mind, apparently.
