First off - I didn't buy these from amazon so this is not a reflection of the vendor, only the product.
I thought these would be good as the different colours would be suitable for different fabric shades. However, the lead doesn't actually leave a mark consistently, even using a good quality pencil sharpener the lead breaks and the already short pencils (about 3 inches maximum I think when new) disappear quickly to unusable stubbiness when you have sharpened them more than three times - which you will need to do, frequently, because they cannot retain a sharp point and you cannot therefore maintain a consistent line. The lids are pointless and fall off the pencil, just cluttering up your storage, and the brush thing doesn't do anything useful. The pencil marks don't brush off with the lid, though they can come off when washing.
I found these quite frustrating, and it might be worth considering other marking tools. I generally still use a (non-splattery) biro, which I was hoping to move away from, or for important things, a fabric pen that came with my sewing machine. However, I'm not sure either of these wash out well, so am still at square one.
Great idea, poor quality product; there are better ways to mark your fabric.