<human>: Goal: How can I use toothpaste to clean my shoes?

Which of the following methods is more reasonable for accomplishing this goal?

OPTIONS:
- Place toothpaste on cleanest parts of shoes and scrub with a old toothbrush.
- Place toothpaste on dirtiest parts of shoes and scrub with a old toothbrush.
<bot>: Place toothpaste on dirtiest parts of shoes and scrub with a old toothbrush.