Having collected flashlights and detailed cars for most of my life, I can assure you that a quality flashlight will do the exact thing as a flashlight with a "Swirl Finder" sticker slapped on the side.
Looks good!
While I think all these companies releasing these headlight repair kits are remiss if they don't include a permanent sealant to replace the clear coat, I think the 3M kit is the most effective one in terms of getting the lenses clear again.
Well, grease is hydrophobic, but, as I remember well from my youth and wearing good old Murray's Pomade, it tends to magnify the sun's rays. Soooooo, yeah. ;)