I picked up 3 rugs and each have small dark urine stains that won't seem to lighten up even with a good wash. Any suggestions?
Could there be blood in the urine. It looks like blood to me but the picture is small. Barry http://www.spongobongo.com
Could be the pet was on meds, I've seen pee get really dark, and really hard to remove the stain. I've seen it quite a few times and was not always successful with chemical removal. And you sure can't patch those.
Definitely avoid the USR on wool. If the dyes are colorfast, I would do a long soak in Bridgepoint's new Wool Medic prior to your regular cleaning process. Use a mild oxidizer as a last resort if needed and you have the owner's informed consent.
If the urine had blood it in it, the iron within the blood might have left a rust stain. Not sure about wool, but rust remover may help.
Felds Laundry Bar soap is good for taking most stains out of carpet. I have had good luck. I have never tried it on wool and I do not know if you can use it on wool. You might try it on an old rug that is junk before you try it on others. Be interested to see how you come out on this and get an update.