String Cleaning-
If you must remove the strings from your bass, you're really going to be better off just buying a new set i.e. you'll never get them back on your bass precisely, as they were before so the overtones will, get....skewed.... That said, (I would)clean them on the bass, using a good clean cotton cloth i.e. T-shirt, "wet" with denatured alcohol. I'm not suggesting you do this, as I don't answer calls from your lawyer, but it is, the smart way to get this done.
If you must remove the strings from your bass, you're really going to be better off just buying a new set i.e. you'll never get them back on your bass precisely, as they were before so the overtones will, get....skewed.... That said, (I would)clean them on the bass, using a good clean cotton cloth i.e. T-shirt, "wet" with denatured alcohol. I'm not suggesting you do this, as I don't answer calls from your lawyer, but it is, the smart way to get this done.