Sorry to say but it seems that lessons are learned and remembered by making mistakes, sometimes big mistakes.
When not sure how to clean and polish a pair of shoes the “don’t do anything” is good advice. Until the correct procedure is determined, it is impossible to ruin a pair of shoes. This saves upsetting oneself, the member or guest; embarrasement; paying to replace the shoes.
There is nothing wrong with admitting to not knowing how to do something. It actually shows character.