If either the package or the condom is flat, cracked or looks dried, the condom should not be used. Lubricants like K-Y Jelly should be used with condoms. A condom should be used only once and then it should be discarded. For highest effectiveness, condoms should always be used with a vaginal spermicide . There are a number of insertable spermicides-creams, jellies, suppositories, sponges, and foam, all of which are intended to block the cervix and kill sperm.
Effectiveness varies greatly.
These products are often labeled unclearly, and it is not always possible to be sure whether they are meant to be. Vaginal contraceptives are most effective when used with some form of barrier method such as a condom and should never be used alone. Another important part of safer sex practices is the dental dam. The dental dam is a square piece of thin latex, much like the latex in condoms, that is used to prevent the transmission of STDs when oral sex is performed on a woman. When used, the dental dam is stretched across a woman's vagina to prevent exchange of bodily fluids.