I've used seafoam on most of my cars to help clean up carbon deposits, i'd imagine its safer to use the ethanol, its petroleum based and claims to be O2 sensors safe and all...every so often I'll use a can on my car, 1/3 in the gas tank, 1/3 in the oil right before the oil change to loosen up any gunk, and then the last 1/3 is poured SLOWLY in threw a vac line, the PCV or brake booster is best usually...after that you let the car sit for 5min or so and then start it up and it will smoke heavily for a few min, this is normal lol I did it and personally have noticed differences in vehicles afterwards...I will caution you some people have had not so good experiences with it, I have only had good ones, but I will say use at your own risk...
Here is the link to the site, you can get it at most auto parts stores
http://www.seafoamsales.com/motorTuneUpTechGas.htm