It shall be lawful for any justice, judge, official, officer or employee of the judicial branch of government, including any retired or supernumerary justice, judge, officer, official or employee, to voluntarily diminish the compensation, salary, retirement benefits or any other benefits of monetary value fixed by law to which he is entitled, from time to time, to such extent as he may desire, on forms and in the manner prescribed by the Administrative Office of Courts; provided, that this provision shall not prevent such justice, judge, officer, official or employee from drawing his travel expenses or allowances, provided he is performing duties or engaging in activities in behalf of the judicial system of Alabama.