I have never had poison oak and travel in it a lot. We do not have poison ivy here. My time may come! So my suggestions may not be too useful to those who are super sensitive.

For what it is worth, when I am in oak country, I take a dip in cold water at the end of EVERY day and NEVER sleep in my clothing that I wear during the day. I remove clothing AS IF I did get it into poison oak, whether I did or not. I have "oak soap" at home but do not take it on trips with me. As for clothes, I just wash them in the washer in warm water when I get home.

You may also consider wearing knee-high gaiters - they are a lot easier to carefully take off at the end of the day and wash out and protect your pant legs from getting exposed.