Actually to avoid tomato sauce stains:
I don't wash plastic cutting boards (the only plastic I have except for childrens' dishware and cups for the nieces, and my Brita "bottle") in the machine when there is red sauce.
BTW=> Heated dry "sets" stains on plastique DW interiors.
Also, this Cascade product [in he following link] has peroxide in it and bleaches your plastics (and DW tub) clean. Leaves a nice pine smell behind too.
http://www.homemadesimple.com/cascade/products/booster.shtml
I don't wash plastic cutting boards (the only plastic I have except for childrens' dishware and cups for the nieces, and my Brita "bottle") in the machine when there is red sauce.
BTW=> Heated dry "sets" stains on plastique DW interiors.
Also, this Cascade product [in he following link] has peroxide in it and bleaches your plastics (and DW tub) clean. Leaves a nice pine smell behind too.
http://www.homemadesimple.com/cascade/products/booster.shtml