There is a ton of info on the net on how to do enemas. Really it is simple. Just let a little liquid flow out the tube before inserting it into the rectum or you will force air into your colon which would be unpleasant.
You might want to check out coffee enemas, as long as you doing enemas. Your last 2 cups could be coffee with the yogurt added then. There is a lot of info on that kind of therapy on the net & here on CZ on bowel cleansing & liver cleansing. Gershon (or Gerson?) therapy is all over the net.
If you are on Netflix see The Beautiful Truth video maybe.
More good news, from my experience enema bags last forever.