Cleaning a Dishwasher from Chametz for Passover

Is it permissible to use a dishwasher that hasn't been used since Purim for Passover? A strong cleaning agent is used when operating it.

I am quoting what our teacher, the Gaon, Rabbi Ovadia Fried, shlita, wrote on this matter: 

Question: A dishwasher that is used throughout the year, can it be kashered for use on Passover?

Answer: There are those who are lenient and allow it to be kashered by thoroughly cleaning all the crevices, waiting 24 hours, and running a cleaning program [without soap] at the highest temperature. Additionally, special racks for Passover should be used (since for plastic, boiling may not be effective), and there are those who are lenient and kasher the racks by leaving them in the dishwasher during the cleaning program (and this is considered as pouring from a primary vessel). However, ideally, it should not be used and should not be kashered.

In the case where you are a guest on Passover at others' homes, and food is served that was cooked in utensils washed in a dishwasher kashered for Passover, it is permissible to eat it.