Now my mother has had the same one for at least 5-6 years, she has never washed it with dishwashing detergent, but simply wipes it off with a damp paper towel after using it and it comes right clean.

Cookie sheets not durable (Rating: 2.00)
Review : I got this as a wedding gift. I do not know if it cooks well, as I have not used them yet. I did run them through the dishwasher, as I wash things before first use. On the bottom of the cookie sheets, they say "Dishwasher safe - Do not soak in water" and "Caution! Do Not use if water is inside pan layers. Risk of burning from steam release. To remove water, place pan upside down in oven at 250 F until water is gone." On it's first round through the dishwasher, one of the cookie sheets got water in it between the pan layers. So now I have to stick it in the oven for a while. I will not be happy if I have to do that every time I wash the cookie sheets. Also, the tops of the cookie sheets scrape easily (I stacked one cookie sheet on top of the other, and if you slide them at all, they scrape the tops). Although still usable, I am not impressed with the low quality of the cookie sheets.