How long....Silver....How Long?

I bought an Analysis Plus Silver Ovals speaker cables( used). Right now, I have it connected for 24 hrs. straight playing music. The sound is okay but not impressive, it's a little bit harsh still. From one of the posting that I made, a member commented that for silver, it takes longer to "break in" the cables. My question is as follows:
1. For used cables(such as mine), does expected break in periods still apply?
2. Roughly, how long should I wait until the cables shows its natural sound? Or at least a hint of it.
3. Is it premature to say that the cable is not a good match in my system?

all comments and suggestions will be greatly appreciated!

thanks