Yeah but it was much more expensive than canola oil locally and much more viscous. I needed something I could get immediately close by. I also read that mineral oil is corrosive. Mineral oil might last longer than canola oil but I didn't need to use it for very long. 

 I was reading up on it last night and found this https://www.researchgate.net/publication/305525405_Effects_of_mineral_oil_immersion_cooling_on_IT_equipment_reliability_and_reliability_enhancements_to_data_center_operations

Hard to get a clear consensus from forums, some said mineral oil good, some bad, miners advised against in favor of $100/gal stuff 

 The expensive dielectric is definitely superior to any other option.