The biggest walmart here(supercenter) has a lot of set in clearance, but with 0 or 5$ markdown. Have three here, one puts everything in clearance at 50%. Everything included legos. The third and smallest one, i've found the better deal up to 80%. But they kind of clear by alot sets that they have 1-2 copy for space need. The ones that they have 6-7-10times, they only reduced it by 5$ -10$. Went there this morning, didn't take anything tough already bough my quota this week. But if lucky, the 16 I might get an other jokerland at 50%, some ninjago sets 40-50$ instead of 75 and 90$... there is two millano at 65$.. i don't have any(sold them) and I regret not having one... might grab them.
So, the supercenter didn't do any clerance yet, checking often, but they are the slowest beetween them. Maybe they just don't need shelf space like the two others needed.
My best trick is to spot some clearance sets that are available on the walmart.ca store tracker... check often(many time a day). I grabbed very close to 100 sets at 50% or more like this pass two month or so. Nothing is free of work. Some people ask me how I do this, how i manage to find to deals and grab them so quickly.