This is still being tested.  One method that has been found effective for the removal of some spray paints that have been sprayed onto the Gentoo is to use a soft sponge and xylene, followed by a clean rag and more xylene.  Other organic solvents may work in place of xylene.  Proper safety precautions must be taken when working with any organic solvents.  In some cases, the paint has simply been peeled off of smooth surfaces. Pressure washing or physically rougher (or abrasive) cleaning materials may remove the Gentoo.