No bottles, no leaks, no 100ml limit to argue with.

Why it earns its carry-on spot
Solid bars solve a problem that decanting into travel bottles never quite does. Nothing to leak into a suitcase, nothing to declare at security, and no sad half-empty bottle of hotel shampoo as the backup plan.
Rice water is the ingredient story here, long used for strength and shine, and the bars lather more generously than most people expect from something that looks like soap. One bar lasts considerably longer than the bottle it replaces, which makes the plastic saving a genuine one rather than a token gesture. Practical first, and better for the bathroom shelf as a side effect.
WHO’LL LOVE THIS
For the traveller, the minimalist, or anyone tired of leaking bottles.
The Carry-On Only Traveller: No liquids, no plastic bag, no limits. It removes an entire category of packing decision.
The Plastic-Conscious: Swapping two bottles for two bars is one of the easier changes to actually stick to, because nothing about the routine changes.
The Gym Bag Packer: Nothing to spill over your clean clothes, which is the recurring problem with a bottle in a kit bag.
The Long-Hair Owner Chasing Shine: Rice water has a long history behind it, and the bar format means it lasts a lot longer than a bottle.