Detergent container with thermo-chromatic level indicator

A method of manufacturing a container which contains a solid block of chemical within an upper portion of said container, said container having at least one internal surface, said solid chemical being a detergent for the washing of dishes, ware, laundry or hard surface, the method comprising the steps of:

• (a) providing a first plastic material, approximately ten percent of said first material comprising a thermo-chromatic additive;
• (b) providing a second plastic material containing no thermo-chromatic additive;
• (c) combining said first and second plastic materials as outer and inner layers, respectively, in a coextrusion process so as to form a hollow container;
• and
• (d) filling said container with the solid chemical, said chemical having an eroding surface, said thermo-chromatic additive being selected so as to exhibit a color change at the level of said eroding surface responsive to a warm water spray.