"The flaxseed oil that you buy seems to have some particulate matter that is noticeable in the finished seasoning." I'm guessing that you buy unrefined flaxsee

"The flaxseed oil that you buy seems to have some particulate matter that is noticeable in the finished seasoning." I'm guessing that you buy unrefined flaxseed oil, and that you keep it refrigerated? That's what you should be doing, and it's all well and good. But unrefined flaxseed oil contains a mix of fatty acids with different melting points. Some of these solidify under refrigeration, and give the appearance of being particulates when poured or used.