Wudū' is a form of worship ritual, which means that it is meant to be followed as is without trying to figure out the wisdom behind it or its impact. In other words, it would be what one would consider symbolic with one's limited knowledge.
الأصل في العبادات بالنسبة إلى المكلف التعبد دون الالتفات إلى المعاني وأصل العادات الالتفات إلى المعاني
— NOTE: My own translation, so treat with care:
The basis of worship rituals, in relation to the performer, is to worship without reverting to intention [of its prescription]; whereas, the basis of habits is to consider their intentions.
He then elbaorates that trying to read into the reasons using one's logic does not yield much. For example (the examples are Al-Shātibi's):
- Purification extends beyond a direct connection to impurity.
- Prayers are defined with specific actions at specific times; if done with actions other than specified at the specified times would not be considered prayers.
Purification can be done using water (tangible cleanliness), or dust in case of tayammum (intangible cleanliness). Therefore, it is obvious that cleanliness per se is not the desired outcome of the purification ritual.
Finally, Al-Shātibi concludes by emphasizing that the objective of worship is to show total submission to Allah's commands, whether one understands the logic, reason, impact, cause, etc.,or not. It is to exalt Allah ﷻ, and to worship Him within the boundaries He defines and in the manner He defines.