How do you encourage individual to keep their clothing and personal care items clean safe and secure?

If you're a parent or a spouse, try asking his/her peers (pals) to talk about it and ridicule slobbiness. Peer pressure works wonders. If that doesn't work and you've also mentioned it directly, you may just have to live with it. Try pointing out the advantages and the examples of those he respects...but stop short of nagging. Eventually he/she might have to learn through experience.