I have to wash a few things out.
1. Lit. I have to wash things by hand, such as socks and underwear. I have to wash a few things out before I go to bed. She has to wash out a few things.
2. Fig. I have to do something (that keeps me from spending time with you). Jane: Time to shove off. I have to wash a few things out. John: Bye, Jane. Bill: I have to wash out a few things. Bob: Why don't you use a machine? Bill: Oh, I'll see you later.