After reading the reviews I was a little hesitant to try this on my boots, but I had an old pair that have been worn through all sorts of mud, rain and snow.  They looked pretty bad and I figured it couldn't get much worse, so I washed them with this cleaner and conditioner.  They certainly don't look brand new, I didn't expect they would, but they do look 100% better!!  I sprayed them with the UGG Water & Stain protector once they were dry.  Brushed the nap up and the rains came...I wore the boots for the last three days walking on soaked ground and they are...not leaking at all!  I'd decided to just toss them because they had been leaking so badly, I'm glad I tried the UGG products.
If you have suede boots try this on them.  It worked great on my boots and if and when I need to wash my new UGG boots, I won't worry a bit.