A clear vase makes the roots of lucky bamboo easy to inspect, until deposits and debris obscure the view. Plan the cleaning before lifting the stems so they are not left unsupported while you search for another container.
Use a clean temporary vessel and handle the roots gently. Remove loose debris without scrubbing or pulling at living root tissue.
Record the water level
Before emptying the vase, note how the plant was supported and where the water sat around its roots. Reassemble a stable arrangement rather than burying the stems more deeply because the glass looks empty.
Choose water appropriate to the plant and local supply, and keep the container away from an unsuitable hot or dark position. Clear water alone does not prove that every growing condition is right.
If a stem is softening or roots are deteriorating, investigate that separately. Cleaning the vase improves visibility, but it is not a treatment for every cause of decline. Keep the plant's identity attached to it too: lucky bamboo is a dracaena, not an instruction to follow the care of outdoor bamboo.
Related reading: Lucky Bamboo in Water: Light, Water Changes and Feeding.