Help with a materials engineering project in the university

Dear readers and colleagues,

We are Materials Engineering students at Ben Gurion University in Israel.
In our studies, we have a project which we need to do in Solid Works.

We decided to build a stick that helps cleaning high places such as door lintels.

Our idea is to put a small water container inside the handle of the stick, and with some kind of a straw or pipe to withdraw the water on the other side, where we will add a rag.

As first year students, we don't have enough knowledge about the materials and the mechanical systems that we can use in order to build that.

We have two main dilemmas:
1- What kind of straw should we use that will be elastic, flexible and durable (we want the customer to change the length of the stick as needed)?
2- Which mechanism should we use in order to withdraw the water from the container to the rag (the handle should be in the lower part of the stick and the water will exit from the top side)?

Of course we will be more than glad to hear more ideas and possible ways to improve our product.

Thank you in advance!