condoms+withdrawal+spermicide

[brad]

My question is regard spermicidal condoms. I have used the regular lifestyles ribbed versions and it fits me quite well.
I normally use ribbed condoms plus the withdrawal method as a secondary method. In other words, i dont ejaculate in her...i pull out before. So all the condom may have in it is pre-cum.
1. I would like to know if spermicide condoms have enough spermicide in them to add further protection by nullifying small amount of sperm in precum? (of course i have read your buddy system article)
2. Secondly, if not, would it be practical to coat the condom with some spermicide gel before insertion just incase?
3.Im aware that condoms plus withdrawal is 99.92% with perfect use,would spermicide condoms or coating it increase effectiveness?
4. Why is it that perfect use condoms are 98% and spermicidal condoms are 97% effective? What causes the difference?
Thank you
(jus trying to reduce risk best i can,may seem like over analyzing)

[Onionpie]

Hi brad. Studies have found that condoms that come with a small amount of spermicide are not any more effective than any other kind of condoms -- ie. the tiny amount of spermicide on those condoms might as well not be there.
Most spermicides (gels, foam, etc) are actually inserted into the vagina instead of coated on the condom. Using spermicides that way can be a good back-up method for your condoms, more so than using spermicidal condoms.
I think the 1% difference between the two types of condoms may just be due to slight variation in research results, as in, sometimes you will get very slightly different results even if you do something exactly the same (like when you're doing a science lab at school and have to plot a "line of best fit" between the data points because they're not QUITE exact). But I'm not a scientist, so that might not be it

Here's our little article about spermicide with even more info:
Birth Control Bingo: Spermicides

Hope that helps!