hydrogen peroxide is the recommended product for removing blood. You can buy it in any drug store.

HP...got it....will report back......thanks.

I would use sodium percarbonate so HP might do the trick.

Usually an enzyme type product will remove blood. Maybe you need to let the Zout sit a little longer.

BacOut from BioKleen would do it I'm sure.

Here is a link that might be useful: BioKleen BacOut

@asolo, be careful not to "bleach" the carpet with percarbonate or HP. I've done it before :)

OK...a little breathing-time, at last.

Thank you, graywings, for HP suggestion. I had some on-hand and let it sit on the spots for a minute or two before using machine again. Result VASTLY superior to anything tried before. Will have to wait until dry before final pronouncement but looking very good right now.

Thank you for quick response, graywings. You've made a very troublesome evening quite a bit better. Thanks, too, livebetter, for follow-ups. Pretty nice of you.

To make a "shampoo" that ges out organic stains including blood and anything from pets, etc, mix equal parts of water and hyrdogen peroxide, add a splash of Dawn dishwashing liquid. Make it in a big open container (I use a plastic pitcher) as it foams up and might explode a tightly-tapped container. Apply with a scrubbrush or pour on the stains, rub but don't damage the fibres of the carpet. Soak up with towels.

And if you make my carpet shampoo reciPe (above), don't store it . It only works when fresh. Throw out any you don't use. I'm mix a bottle of peroxide, a bottle of water and a squirt of Dawn, use it, discard any extra.