[masraum]

I wouldn't bother with chemicals. I'd go for a snake. I assume the drain for the washer is easy to get to, so I'd probably start the snake there. I'm sure the kitchen sink and washer are on the same drain line, so whatever is blocking one is also blocking the other. Starting at the washer seems like it would put the snake closer to the clog. I never bother with the cheap, short snakes. I always go with something like the following. I look for the sleeve at the front that's got the thumb screw to be metal, and I look for something that's 25'. I know there is better, more heavy duty stuff, but that's always worked for me and if it didn't, I figure it's better to call in a pro.