For my part, I would not use anything with the word "soap" attached to it for sheath cleaning.
A lady posted on one of the message boards I belong to, that she uses KY Jelly instead of the Excalibur Sheath Cleaner.
That way if she isn't able to get That Part squeaky clean, it won't hurt the horse.
I had some explaining to do when hubby saw THAT in the WalMart bag
Another trick I learned from one of these boards is to spray a mineral oil/water mix up inside the night before the sheath cleaning is to be done. That gives the smegma a better chance to loosen up and makes for faster, easier cleaning
Maybe this is why I never get excited about spring? I have always had geldings