Yeah if i were to use Lanturn in OU, i would run Rest / Sleep Talk / Scald / Heal Bell. With Heal Bell Lanturn is one of the few pokes that can viably run a RestTalk set, as it has a 33% chance of waking up in the first turn, and a ~56.5% to wake up in the second which is really nice.
Also about Skill Swap Chansey vs Reuniclus. It doesn't matter that it gets cured of Toxic when it switches out, as you can beat it 1 v 1 and this is all that matters. So, slowly beat every other poke, and let Reuniclus as the last mon, and you won.
Part of the OU QC team, message
me for a check!