Contact time required for each sanitizer?

Just curious as to everyone's process for sanitizing. I usually fill my primary fermenter to the brim with water and then add the appropriate concentration of Bleach or One-Step. Then I drop all of my equipment in there and let it soak for a while. (I make sure my tubing gets filled with the stuff--no air bubbles--and I flip my tall spoon so that both ends get sanitized).

I never really know how long the stuff needs to soak. I usually leave it for at least 20-30 minutes perhaps this is overkill? Does anyone have advice on how much contact each sanitizer needs in order to do its work (Bleach, One-Step, Star-San, Iodophor, etc.)? Do any of these solutions sanitize *instantly* or within a few seconds, or am I right in letting them soak for a while?

Also, am I wasting my bleach/sanitizer/water this way? Can I just mix a small bowl of solution and then wipe everything down with a solution-soaked paper towel (as opposed to my 7-gallon-soak approach)? Or put it into a spray bottle and spray it down? (I've seen the spray-bottle thing mentioned here before but I didn't know whether it's for full-gear sanitizing or just spot-sanitizing).

Any advice would be appreciated.

Thanks,
chris.

Iodophor and Star-San both have very short required contact times. I've heard different numbers for each, but they range from thirty seconds to maybe two minutes (most people say closer to the former). They also do not need to be submerged for the entire time, it's generally sufficient that they're wet, or in the case of Star-San that they are in contact with the foam.

I don't know that I would trust any of the sanitizers we use to simple get a wipe-down with a wetted paper towel, though. I'll fill a shallow Rubbermaid container with some Star-San and soak little things in that, put a little in the carboy or bucket and shake it up/roll it around inside.

With the Betadine solution I use I submerge for 30 seconds or wet/slosh/shake for 1 to 2 minutes

Here's a decent summary:

http://www.howtobrew.com/section1/chapter2-2-3.html

Star-san works in 30 seconds of wet contact. The EPA makes the creators state something like 2 minutes, primarily due to commercial use.

Most home brewers are on a small enough scale that everything can be wetted in 30 seconds.

You mentioned wasting sanitizer. I fill a gallon jug with Star San and pour some into a wall paper tray and soak all utensils in it and pour some ( about a pint into the carboy and slosh it around. After the brew I pour it back into the jug and use it for transfer and later when kegging or bottling, I use only 1/4 ounce per batch