The docs kindly offered up some of their own personal favorites, too. About a half hour before you have relations, you just gotta douche with soda water. This is from a Native American ceremony and it really works when you are of different races. Tried it once, but couldn't stomach it. The problem is that in many cases, alternative medicine has not allowed its treatments to be subjected to the same scientific scrutiny and standardization that traditional medicine has, making evaluation of its claims impossible.
Sugar is probably only a real problem in diabetics.
Even in these cases, the best bet is probably to go to a reputable reproductive endocrinologist and have the sperm appropriately washed and inseminated. After 30 minutes, sperm that are not already in the cervical mucus are very unlikely to survive. Ejaculating more often than 36 hours may lead to a lowered sperm count and temporarily decrease a man's fertility. As long as ejaculation occurs deep in the vagina. This technique will most likely result in poor quality sperm being delivered, often after ovulation.