I'd say slurp half a can through the PCV valve, put maybe 1/4 to 1/3 of the other half in your oil (and change your oil/filter within 500 miles), and then dump the rest in your tank. It does work well to clean the carbon poopie out of your crankcase, because it's a VERY effective detergent, and your oil will be MUCH darker coming out with all that extra gunk when you drain it ... but I would NOT go dumping an entire can in there and then driving around on it for 3,000 miles - good way to chew up things you do NOT want to get chewed, y'know? (Seals, gaskets, bearings, etc.)
Putting more than 1/2 a can through the PCV system is kind of overkill. When you shut the motor off and let it soak for awhile, as per the directions, the engine can only hold so much of that (realistically) on the motor's top-end. If you try dumping too much of it in there, too quickly, you'll hydrolock the motor; if you put in more than 1/2 a bottle and do it slowly, you'll just be wasting a lot of it, because it's only going to take off so much carbon while it's running through there, anyway.
IMO, the least effective treatment of the three methods is pouring it in the gas tank - it doesn't do much more good than running it through the PCV system, and it's certainly no more effective than a dedicated pour-in fuel injector cleaner. At least with the other two methods (crankcase and PCV), you'll wind up with visible cleaning results.
Putting more than 1/2 a can through the PCV system is kind of overkill. When you shut the motor off and let it soak for awhile, as per the directions, the engine can only hold so much of that (realistically) on the motor's top-end. If you try dumping too much of it in there, too quickly, you'll hydrolock the motor; if you put in more than 1/2 a bottle and do it slowly, you'll just be wasting a lot of it, because it's only going to take off so much carbon while it's running through there, anyway.
IMO, the least effective treatment of the three methods is pouring it in the gas tank - it doesn't do much more good than running it through the PCV system, and it's certainly no more effective than a dedicated pour-in fuel injector cleaner. At least with the other two methods (crankcase and PCV), you'll wind up with visible cleaning results.