If you'r going to teach them anything at all, teach it ALL to them. Abstinence IS the safest policy. Teach them about the protection, but that's not enough. Make a field trip to the HIV/AIDS ward at a hospital mandatory with the class. Let them see the possible consequences of irresponsible sexual behavior.
The Bush League is pushing Abstinence Only Sex Ed, to appease social conservatives. You have described in general terms the Abstinence Plus Sex Ed program, which has a much better track record. I'm not sure if it has the "scared straight" component, though. Most, if not all, liberals, endorse Abstinence Plus.
Welcome, gunny. Turn away from the Dark Side.