I agree with everyone that the CNA sounds awful, but the shaving cream is a trick I learned in clinicals in the ICU. Believe it or not, it really softens the skin and smells great! It rinses easily also, whereas soap is hard to get off in a bed bath situation.
In my opinion, you did learn something in this sad situation. At the very least, you learned that you can learn something from everyone. Even if they seem to be useless, they may have some little nugget of information that you will use later as a nurse. Or, if they are completely useless, at least you are learning how you do not want to practice nursing.
I'm glad that you are questioning practices that seem off the wall - don't lose that! Good luck!