What I'm going to tell you now is highly controversial and, if seen by those in power at BC Towers will likely get me thrown out of the group.
But...
For a short term solution to get that bright, new string sound, pop your old strings in a pan of boiling water for a few minutes. Dry em very well, get em back on and bingo, you have brightness again. Probably only last for a few days, but it's a quick win. Used to do it all time when I was a youngster and couldn't afford new strings.
Keep it under your hat though eh..? 😉😬