All I can relay and post are my own observations from using Kreen. BTW...this was the first time I used any kind of engine cleaner.
On the first oil change after using Kreen, on a high speed run for over 1K miles, the contents of the oil filter caught my attention. The remains of the oil and Kreen, after looking and spilling out the contents of the Bosch D+, oversized oil filter, was the consistency of a very watery "Pudding" or "Jello" that fell out of the filter in a "Plop".
I really don't think that this was a chemical reaction of the oil to Kreen but rather the dirt, carbon and varnish that was trapped in the filter. The sump drained with a fury when the drain plug was removed and the contents were black like carbon, and a watery flow. The engine was very hot, I might add, when the oil was changed on both runs.
The second run of Kreen....I did not have the build up in the filter and the oil, when drained, from the pan came out very brown....but I could see through it like I was wearing brown sunglasses. No foreign matter to speak of was in the drained oil as I watched the stream of oil go into the catch pan.....just a light thin oil.