has anyone had any bad experiences with gunk motor flush. its that stuff you add to your engine and run it before you change your oil to get rid of varnish and other crap builds up in the engine. i dont want it to eat away at any seals or any thing in my engine. anyone know any good ways to clean out my engine? should i even bother cleaning it? my brain hurts. ow.

Why do you want to flush/clean out the inside of your engine, do you suspect something is wrong?

I know it may sound to obvious but changing the oil and filter frequently will do a lot for cleaning out the engine. Sorry, no experience with additive cleaners.