On a serious note, since the OP and a couple others mentioned "Fast Fret," it's worth noting that behind the fancy packaging, Fast Fret is essentially nothing more than mineral oil. It would be more cost effective to just pick up a bottle from your local pharmacy. I always have some around, as I use it for treating rosewood/ebony fretboards, and for cleaning/sealing wood cutting boards, wooden knife/tool handles around the house, etc. My brother plays double bass and uses mineral oil from time to time to clean the rosin and general accumulation of gunk off his strings. I've never felt a need to use it on electric bass strings though. Then again, I have been using flats on both my Jazz and my P for a while now.
'89 Sunburst MIJ 62RI Jazz. '92-3 MIK Standard Precision. De-fretted Squier Std. Jazz.
Hartke HA550. Ampeg PF500/PF210.