Spermicides and contraceptive gels are inserted into the vagina before marital relations. They do not kill sperm cells, but rather create a hostile environment that reduces their motility.
Spermicides are used on their own or in conjunction with barrier methods of contraception.
Spermicide comes in a variety of forms, including film (VCF), gel, cream, foam, or vaginal suppository. Contraceptive vaginal gel (Phexxi) works similarly, but has a different chemical formulation.
Spermicide is typically available over-the-counter, while Phexxi requires a prescription. Spermicides and gels need to be inserted before relations (generally at least 10-15 minutes, but no more than an hour, depending on the type).
A list of pharmacies in Israel that carry VCF, a particularly effective form of spermicide, can be found at https://www.safevcf.co.il/wheretobuy.