A lot of produce absorb the chemicals, so no amount of cleaning will remove that.
As an example, I am allergic to something which is on/in melons. I developed an allergy, or so I thought, to melons (cantelope, watermelon, honeydew, etc) five or six years ago. Once I started eating organic produce I found I could eat the melons just fine if they were organic, but I still have an allergic reaction to the "conventionally" grown melons.
Some fruits/veggies are only sprayed and absorb very little. There are lists about ones which are usually loaded with chemicals, I remember strawberries being one.