Hey Mark
Canola or rapeseed is OK...try thinning it with 25-33% kerosene and see if that helps. We use it on our mortisers without problems and apply with a spray bottle. Chainsaws are more forgiving but they're effected by temperature, which can prevent good flow to the bar...as I'm sure you already know, that's why there's a difference between lighter winter oils and thicker summer oils for chainsaws.
You can buy veg-based and environmentally sound bar oil that's specifically made for chainsaws (originally designed for use in watersheds and sensitive areas) All the big suppliers (Huskie, Stihl, etc) sell this now. Check out:
www.renewablelube.com if you're interested.