Will I need to wash my hair more frequently with a shampoo bar? 16 January 2023 18:38 Updated No. Most people find that they can wash their hair as often as they used to with liquid shampoo. Related articles Will the shampoo bar leave waxy residue? Will you have a conditioner bar? What hair types is the shampoo bar suitable for? Does a shampoo bar work as well as liquid shampoo? How long will the bar last?