Did you know that traces of finished soap act as an accelerant for any fresh soap batter with which it comes in contact? To remove soap stuck inside your SB bell, simply soak it in hot water, and then run it on top speed in clean hot water. If that doesn't clean it out, you need a new SB.
Ceramic crocks and stainless inserts used in slow cookers are non-absorbent. If you wash and rinse them properly, there should not be residue of anything left on them. And again,
you wash them with soap, whether that is your homemade dish soap, or commercial detergents that are loaded with scent and color.
Again, I do recommend dedicated equipment for those who are selling, but for a hobby maker, you are not endangering your food in any way as long as you clean things properly and use non-absorbent items.
JM2C