No they don't wash out bed bug guts but I live in the city and my problem is dust, dirt, exhaust particles and the like. These pills work well; They're a lot easier to store than gallon jars of this stuff, and you can't beat the price. PRO TIP: I keep a used water jug, and when it's time to add washer fluid, I put a pill in the jug, add some water, and shake to dissolve the pill. Then I fill the rest of the pitcher and pour the blue juice into the machine.