Hi new user here. Just thought I would chime in with my own experience using Canola. I only make soap as a hobby for personal use and I never sell it.
In the UK it's just called 'rapeseed oil'. I am referring to the refined version that is the main constituent of generic 'vegetable oil' that you buy in the supermarket. Currently it's pretty cheap at about £2.80 per litre.
I like to make a 100% canola bar and use it in the shower. Pros of this are:
- as mentioned above, it's dirt cheap
- locally produced. Very important to me as between this, lard and tallow I can make a pretty sustainable bar of soap here in the UK. I do use coconut oil in hand soaps however.
- it makes an ideal 'shampoo bar'. It doesn't make your hair squeak or turn into straw like other soaps do. (disclaimer: I have short man-hair so I can pretty much use anything to wash my hair). I find it's even better than olive oil in this regard.
- doesn't dry skin/scalp (i.e. 'moisturizing' but I hate using that term).
- produces a very thick, creamy lather
- neutral scent
Down sides of 100% canola bar:
- doesn't work as a hand soap (e.g. next to the sink), especially if you live in hard water area. Just doesn't lather well enough. In the shower it lathers fine with warm/hot water and something else to help (hair, cloth, etc).
Using it complimentary to other oils (e.g. as a substitute for olive oil) it's excellent as well. In this manner it's fine to use alongside coconut oil or whatever as a hand soap.
As others have mentioned, it can make softer bars so I get through them quick enough that DOS hasn't been a problem. I've tried hardening them using salt, but if you try this be aware that any more than 1 tsp per 500g oil kills the lather.
I wouldn't recommend using cold-pressed rapeseed for soap. It has a distinct odour and unless you like smelling that way I would avoid. Also it's more expensive and (probably?) contains more unsaponifiable components. I do like to eat cold-pressed rapeseed though because it's made locally and is way cheaper than the disaster that is olive oil at the moment
So in summary I really like canola/rapeseed and I would encourage anyone who is on the fence about it to try it out. I will probably never bother using olive oil again because the properties are so similar and rapeseed is so much cheaper (and importantly: locally produced).