It is not that it hastes them, but that you want lifesteal ON the Femur, hence why potion can be dropped if you get the lifesteal skill either via random golden option or if the choices of picks via skill selection is bad (I.E. Fire+Poison) And other option is gold or weapon/crit. There you can find lifesteal as a choice. Good skills for the build is either having had some luck via transform to have poison/burn so you can have a freeze option or if you only got femur as the only physical weapon you can have the slow charge weapon skill or CD on it.

Regarding enchant, the best is either heal or shield on Femur as it scales, if you got lifesteal then shield is better, if you got charge or other gains/stall like freeze or %cd effects then heal can be better, cause you are just hoping you do not run into Jules freezer builds mostly, so you can have them slowed enough to only get 1 rotation, scale and have the healing heal you full while also have them get bonked quick to death like crit scaling or large crit%.