Spermicides are less effective in preventing pregnancy than are most other methods, so they need to be used with condoms. Complete instructions for use come with each package of vaginal spermicide. For maximum protection, it is important to use the product as directed. Another application of spermicide is necessary before each addi­tional act of intercourse. In contrast, the sponge is effective for repeated acts of inter­course and can be inserted up to 24 hours before intercourse. It is probably better to shower rather than take a bath after sex when using a spermicide, to prevent the sper­micide from being rinsed out of the vagina.