If you want to re-freshen your old strings, try putting them in boiling water for a few minutes. Sometimes it doesn't work, but sometimes in works great! So it's worth a shot. Good Luck.
Welcome Bonzo. That's a common way to clean strings on the board, although I personally prefer to soak them in rubbing alcohol for a few hours. It cleans and brightens them, and it doesn't weaken them, at least not to my knowledge.
