Motzei Shabbat, my wife did a load of laundry without realizing that the 9 days entails not Laundering clothing. Because this laundering was not intentional, are there sources which permit my wearing the pants? (I have a pair of shabbos pants that I can wear in the meantime, however it is normally what I would wear) How about if this affects Shalom Bais?
Doing laundry is not permitted for Ashkenazim, hoever if it was done by mistake the clothes are not essentially forbidden to wear, however thgey may not be worn in toier freshly laundered state. (The same as when laundry was done before Rosh Chodesh.) There are two differant options to make the pants wearable for the nine days, the idea behind both of them is to remove the freshness of the laundered pants. Either you can put the pants on the floor for an hour, or to put the pants into the dirty laundry so that it will lose its fresh smell.
Minchas Yitzchok 10-44, Teshuvos V’hanhagos 5-170, Hallichos V’hanhagos pg. 8,