A shampoo bar can replace the liquid shampoo step, but it also changes what happens after the shower. Instead of closing a bottle, you need somewhere the bar can drain and dry. If it sits in a puddle or stays sealed while wet, the tidy, compact product can become an inconvenient soft lump.
A hotel I return to in Korea provides shampoo, conditioner and body wash in bar form. I have found them convenient for a night or two, and I like not having another plastic bottle to deal with. That short-stay experience has made me interested in bars, although I have not switched at home because I am less sure about keeping them dry between uses.
That is the practical question I would settle first. A compact bar is easy to like on a hotel shelf; at home, it needs a draining spot that works for the rest of your household too.
Solid shampoo is a format, not one formula
Bars can contain different cleansing ingredients. You cannot tell from the shape alone whether a product is soap-based, how strongly it cleans or whether it suits your scalp.
For example, the ingredient list for Donggubat's cooling shampoo bar starts with Sodium Cocoyl Isethionate and also includes coco-betaine, oils and fragrance components. That is more informative than treating every solid bar as the same thing as an ordinary body soap.
Cooling is also a sensation to distinguish from a medical effect. A minty bar can feel refreshing without being a treatment for persistent itching, dandruff or hair loss. Choose the cleansing product for your needs rather than assuming a tingling scalp means it is working harder.
How washing changes
The Donggubat directions call for wetting the scalp and hair, making lather with the bar, massaging gently with the fingertips and rinsing well. Other bars may suggest lathering in the hands first. Follow the directions for the one you buy instead of repeatedly dragging a bar through tangled lengths.
Focus cleansing on the scalp and let the lather rinse through the rest. Long hair does not need aggressive rubbing to make a shampoo feel thorough. If the bar is awkward to hold, making lather in your hands may be easier where the product instructions allow it.
How easily a bar lathers can vary. The amount of hair, the formula and your washing conditions all affect the experience. Do not judge suitability by foam volume alone, and do not keep adding more just to recreate the feel of a favourite bottled shampoo.
The storage step is part of using it
Donggubat's storage guidance recommends a soap dish or mesh to help prevent softening. The practical point is drainage: a dish that holds water underneath the bar may look attractive but fail at the job that matters.
Place the bar away from the direct shower stream and leave it where air can reach it. If several people share the shower, choose a spot where it will not be soaked again each time someone washes. A little space between uses can matter more than the number of products on the shelf.
For travel, a container keeps the bar away from your other belongings, but it should not become permanent wet storage. Let the bar dry before packing when you can. If you have to pack it damp, open it and let it drain at your destination. A travel tin solves transport, not drying.
You may still want conditioner
A solid shampoo does not remove the need to consider your lengths separately. If your hair tangles or the ends feel rough, you may still prefer a suitable conditioner. An all-in-one claim on one bar should not be applied to every shampoo bar.
The general AAD haircare guidance is to adjust conditioning to hair type and where it is needed. You can keep your usual conditioner while trying a different shampoo format; there is no requirement to replace the entire routine with bars at once.
When the switch is worth it
A bar is worth considering if you like compact products, have a place for it to dry and enjoy using that format. A bottle may remain the more convenient choice if your shower has no dry storage or you move between bathrooms and pack immediately afterwards.
Claims about how many bottles one bar replaces are difficult to compare without a clear amount and usage basis. For your first purchase, judge the wash, the storage and whether it stays pleasant to use. If avoiding plastic bottles is part of the appeal, keeping the bar dry enough to use it fully makes that choice more practical.