is ok to use Gunk an a clean engine, that has ran through ARX treatments, LC doses, bilstein flushes just to remove old contaminated fluid. I was planning on using it only for five minutes so when i put in my new oil, it would remain new.
Here is a gunk story. A friend was sold an engine flush at an oil change place. I told him not to do it but what do I know I only work in an oil analysis lab. He let them do it. The next day he had a bunch of banging lifters and went to the OC place. That couldnt have been caused by the flush they said. Anyway to get to the end it cost my friend $3000 or a rebuilt engine.
Keep your engine clean by changing the oil regularly and use good oil. If its really dirty the crud that breaks loose will just bugger something up. Same gose for transmissions. Never flush a hi mmmile transmission. You will be in the shop really soon .