lemon oil is not made of lemon. its mainly petroleum distillates but with an added lemon scent to it. its called lemon oil mainly due to its colour.
i personally stay away from autosol. it does wonders to clean up metal parts, but i wouldn't want autosol to seep into the fretboard. I'd suggest steel wool grade 0000 (bought from your nearby homefix/DIY shop), similarly with masking tape.
tape the masking tape at the fretboard (wooden) region around the frets, as close to the fret as possible. get the steel wool and start polishing the frets. the masking tape ensure that the steel wool does not sand your fretboard. i've had perfect results with this. but!
ensure the masking tape is taped as close to the frets as possible
tape up your pickups as well, especially the neck one nearer to the frets. steel wool will be attracted to the magnets in your pickups.
spread some newspaper around where you're gonna do it, so it doesn't get all messy with steel wool fillings around.
Hope this helps.