The phrase "little bleach" refers to a small amount of a cleaning agent called bleach, which is often used to make surfaces or clothes whiter and cleaner. Full definition
Reef were in great shape, very little bleaching and broken coral. (tflats.com)
When I was in college, I carried bleach thru my moms house and didn't realize it was leaking so she had nice little bleach spots on her carpet when she got home and 15 years later they are still there and she always points them out to anyone new who comes in! (theinspiredroom.net)
A little bleach gets the color out of the towels. (epicurious.com)