How effective is spraying?

A tip I got from a video I saw posted online was to mix standard strength sanitizing solution in a spray bottle and use that to to help with sanitation. I've heard some people say you have to soak anything you want sanitized, but some say contact is good enough.
So if I was to thoroughly spray the inside of an ale pale with standard strength Star San, would it have the same affect as filling it ale pale with 5 gallons of water and the appropriate Star san?

On the similar topic of Star San, I get a lot of foam when I use it other than spraying (IE to rinse a carboy out). Yet it says "no rinse." How do I get rid of all the foam?

I also read somewhere (yet cannot find) something that said if the concentration is incorrect, its practically useless (star san). I cannot remember what or where I read that so I'm not sure what to search. Any one have anything to say on this?

Thanks

Yes, many of us keep Starsan in a sprayer. I can be found spraying away at anything that touches my wort once it comes out of the brew kettle. For your bucket it is easier to put 1/2 gallon or so in the bottom and swirl it all around and tilt the bucket to swirl it all along the sides as well. You can also in addition to this spray it down. I believe you want a minimum of 30 seconds contact time for it to sanitize,.

There is no need to worry about the foam. Everybody gets foam, but it is a no rinse so it doesn't hurt anything. Just drain out all the starsan and all the foam that you can, and leave the rest. The yeast will actually eat any foam left behind as food.

Starsan works as an acid sanitizer. If you have not mixed it strong enough it will not be acidic enough to do it's job. Just folow the dillution directions and you will be fine. If you have a way to check PH, you want a PH below 3.5. That is the minimum level of acidity for Starsan to be effective, so 3.5 or lower. If you mix it way to strong it may no longer be safe as a no rinse, so just mix it correctly and measure the PH if you can.

I switched to the spray bottle for Star San, no longer worry about a soak. I spray enough in coating the sides of a bucket that there's enough to cover the bottom. For a carboy, it's easier to pour a little in, and then rotate & move the carboy so that all is covered. With Star San's "coating" characteristic, you're then good to go. Remember, it's all about contact, and as has been said previously, 30 seconds is fine.
The only exception to soaking is that all my small equipment -autosiphon, spoon, spigot, airlock, hose, bottling wand, thief, hydrometer etc.- goes in a 30" wallpaper tray full of SS solution, which is ideal for this purpose, it's less messy that spraying all that little stuff, and it makes sure the sanitizer gets into all the nooks and crannies.
Using this method, I only have to make up a gallon of SS solution at a time, and it will last 3-4 operations. I'm still on my original small (16 oz) bottle of Star San concentrate that I bought a year and a half ago.