Off Meta Does Work but...
It usually works because of cheese factor (the opponent has no idea what to do against what you are playing) or specific hard counters.
this advantage is usually lost outside of lane unless you just crushed the enemy lane. The meta is more set up around the needs of the team as 5 members (need ad damage from range, need tanks, need support, need ap damage) so to were you might smash their lanes if your overall 5 man is very off meta (5 melle, all squishy, low overall damage from building wrong damage type) team fighting could become very difficult and allow the other team to come back from the one or two lanes you smashed. not to mention that usually off meta dose not use the champ to its full potential.
tl;dr: yeah off meta can work but the meta is meta for a reason.