[header] How to rejuvenate a bar of soap [title] Collect a bar of plain white soap. [substeps] It can be the bar you use in your daily shower or a bar under your sink. Try getting one that does not have a strong scent, it may be hard to mask. 
[title] Wash of any dust or dirt off. [substeps] Just in case there is anything, if you are confident your soap is clean-move on to the next step.