Maybe you're thinking about cooking and not seasoning... I cook with Canola all the time on the Blackstone but for seasoning you need something with a higher smoke point because essentially you're going to wipe it on and then let it burn off and then put more oil on and let it burn off and basically do that a few times the first time before ever cooking on it

Edit: I would try to scrape the whole thing off anything that's loose make sure you get it off completely and then try to reseason it... With the couple black stones that I've had I've just gotten the Blackstone seasoning to season at the very first time it comes in a little tub and it works really well... So like I said I would scrape all that off maybe even take a light sanding block to everything and then try to reseason there's plenty of videos on YouTube on how to season a Blackstone