This is a typical activity you would find in any Montessori 3-6 classroom, and at our house as well. O polished some silver pinch bowls we have with a q-tip and toothpaste (the store bought, not mine). It is more about the process and the child being a productive part of the family unit than the actual results of the product. An additional perk for me is this kept her focused at the counter for a solid 15 minutes which allowed me to get a few things done. It is important to me that O can work on these projects with out me hanging around correcting, interrupting (after I started taking photos she politely asked me to 'turn off the light'--ie the flash or to 'give her quiet calm' so she could focus), or intruding on the process for her. Other than when I am giving her a 3-part lesson, I usually give her the activity, with directions in the form of me doing one or two examples (I don't tell her how to do it, I show her). Then I leave her alone. When she has completed the task she shows me and then she cleans up and we choose a new activity.
I am so glad I started this process when she was young (around 15 months) because I need those 5 minutes here and 15 minutes there to make lunch and do chores and have some devotional time. With F being gone, I don't have the evening 'here you take her for a few minutes so I can get X done' that I used to have.