Water (Hadith No. 152)
When it comes to cleanliness, nothing does a better job than water. Not toilet paper, not cotton, not earth (dust) and not even Kleenex. So make sure you use water for your personal cleanliness and hygiene, because tissues and rolls aren’t enough.
Narrated Anas bin Malik:
Whenever Allah’s Apostle went to answer the call of nature, I along with another boy used to accompany him with a tumbler full of water. (Hisham commented: “So that he might wash his private parts with it.)”
We don’t need tumblers these days because taps and showers are available. But if you’re travelling, don’t forget to keep extra bottles/tumblers of water for this purpose. :)