I usually bake it at around 200 degrees for about 30 mintutes to help sterlise it in all my time I have never heard of anyone getting an absess from home brewed gear. Have the oil warm while you filter makes it filter better to. Usually I put the flask in a bowel of warm water to keep. But truth be told in the old days people would put oil in a shot glass with tren pellets a microwave everytime they needed a shot lol and not get absess but that dont mean you should do it. Its hard to get an absess from oil based gear generally.