I would say never, ever use Armorall on your boat!!. The sticky substance you see may be the grease coming from the initial lying of the
lines. Simply wipe it off if it gets in the way. If your
lines become dirty, then a quick (very quick) wiping of acetone or such would be needed, yes, but never Armorall. Not only is it not a "marine product - debates to follow", it increases dramatically the drying out of the vinyl.
Please just wipe down the lifelines and leave the grease alone. Unless, of course, it is a rusty, granular, substance. In which case the boat seller should be called to evaluate.
MaryBeth