Sterilizing pots with bleach - Which method is best?

After a bunch of pepper seeds refused to sprout, I wondered if I had been sterilizing my resused plastic planting cells sufficiently. After cleaning them with plain water (or a blast of the hose) I usually dunk them in a dilute bleach solution before filling with a planting mix that the bag says is sterile. So I started looking up recommendations in DG articles and forums and found a confusing mix of advice. Samples:

1. Dip a minute or longer in chlorine bleach (1 to 5)
2. rinse in bleach solution (1 cup to 2 gal water) then rinse in clear water
3. dip in 1 to 9 bleach solution and air dry
4. Wash in mild bleach/water solution
5. Soak in bleach water then rinse
6. Bleach mixture should break down naturally in soil
7. Bleach breaks down in organic material, one residue is salt
8. Wash in hot soapy bleach water, rinse and drain
9. Clean in 10% bleach solution, soak overnight, scrub off debris, dry
10. Soak in bleach and water with a little soap
11. To disinfect surfaces, takes 15 minutes

All that leads to several questions.
A. Should you clean pots before using bleach? (I would guess this would save on bleach)
B. What dilution bleach solution to use? ( 20% largest quote, 10% mentioned twice)
C. How long to leave in bleach? (Dip probably not enough, overnight seems too much)
D. Must you rinse off afterwards? (If bleach decomposes, why not just let dry?)
E. Should you add soap to bleach. (I would guess no if you clean them first, yes if you don't)

So, I would appreciate any answers (definitive or otherwise!), particularly to questions C and D.

I'll start by saying that if you're already doing some sort of cleaning/dunking in bleach and your seeds still aren't germinating, your problem is likely something else other than un-sterilized pots. If your seeds were sprouting and then dying from fungal infections then I'd be more inclined to blame sanitation (although I'd still look at overwatering first) but since the seeds aren't even sprouting I'd look at things like seeds buried too deep/not enough light, wrong temperature for germination, too much water making the seeds rot before they can germinate, etc first.

But since you asked about bleaching...cleaning the pots would definitely help--bleach does break down in contact with organic materials like soil, so if you don't clean the pot first the bleach may not do as good a job disinfecting as you were hoping.

As far as how to use it, you should read the label on your bottle of bleach for the instructions on how to disinfect (different brands of bleach may be different concentrations and come with slightly different instructions on how much to dilute & how long to leave on the surface). The bottle will tell you what dilution to use to disinfect, and also how long it has to stay on the surface to disinfect.

I would rinse afterwards--the bleach does decompose but one of the things it decomposes into is salt and salt is bad for plants. Depending on how much bleach you used you may not have enough salt to do any harm, but rinsing is something that's quick & easy and certainly won't hurt.

A little bit of soap helps break the surface tension of the water so that all the nooks and crannies get disinfected. I subscribe to a tissue culture newsgroup. It seems that 20% bleach solution is the most common consentration. 10 minutes or so seems to be a common time. This is for tissue that is going to divided

Down here 10% bleach solution is commonly used to sanitize pots, I pre-wash to remove dirt using ordinary dish soap then soak for 10-15 minutes in bleach solution, then allow to air dry before using or storing in a sealed garbage bag for later use (keeps the clean pots "clean" and free from mold spores).

Thanks for the info. Small print on the bleach bottle suggests what I calculated to be about 5% solution. From your suggestions I'll use 10% and 10 minutes from now on...that's easy to remember.

By the way, I kept the trays moist and a month after planting, about 4 out of 48 seedlings finally struggled up to daylight. Don't know what went wrong, I never had to wait that long before, and similarly planted tomatoes popped right up.