Besides not contaminating your plastic brewing equipment (siphon hose, racking cane, etc), I am not sure that would really make a sour enough beer. Only giving the lacto 24hrs then boiling it will not even make it sour enough at all. Even with a strong, large, healthy pitch of just lacto, it will take the beer several mos to reach its proper sourness, if not more. Lacto is a slow, weak, souring agent at least in what I have observed.
Sure Lacto is slow to work in beers at cellar temps. At optimal temp in a super sugary solution, it may work much faster. Look, I saw it in a magazine that I subscribed to off the internet. It has to be correct.