do a google search on how to solarize your soil.

rinsing the soil doesn't work. bacteria are "sticky" and will reside in the soil no matter how much you run water through it.

You can contract several diseases and parasites from cat feces found in your garden soil. If the area contains perennials, it would be wise not to solarize the soil in that area or you will certainly lose those plants. If the bed is an annual bed, I would solarize it as mentioned above. Toxoplasmosis in cat feces will remain infectious for about a year, depending on the conditions. Turning the garden bed under will help to hinder transmission of any diseases found in the feces. If you do decide to plant in the bed this year, just make sure you wear a good pair of rubber garden gloves and be certain you wash your gloves and hands thoroughly afterwards. If you are or plan to become pregnant in the near future, treat that bed as you would a litter box during pregnancy. In other words, don't take the chance with your unborn child.

Before anyone gets too frantic about catching disease from cat feces, call your local health dept and ask them how many people in your area have contracted any disease form stray cats. My county health dept told me they had no information on anyone getting sick from contact with cat urine of feces. (A few infections from cat scratches.) They do recommend pregnant women and young children take precautions and everyone should wash hands carefully.

People choose strange things to be afraid of. For example all gardeners are afraid of tetanus. There were 3 cases of tetanus in 2005. Very unlikely if you wash thoroughly.
Marnie