Unrease activity

You have not provided enough information for most people to answer your question. To answer you quite literally, there are millions of experiments that do not require that you "start with green water and green urea solution." So the short answer is, "You don't."

Here are some questions that will probably start you in the direction of answering your question:

How are green water and green urea different from regular water and urea?

By "unrease activity" do you mean urease activity? Is urease an enzyme?
What does it do?

Is this what you mean by green water (http://www.worldchanging.com/archives/004494.html) and green urea (http://www.incitecpivot.com.au/greenurea.cfm)?