To avoid cross contamination use the following tips. Ideally you should have different coloured sponges and cloths for wiping surfaces and washing up. Make sure you have a chopping board for preparing meat and one for vegetables and always try to immediately clean down surfaces after food has been prepared on them. If you have accidentally used the wrong sponge or cloth or just want to make sure nasty germs have been eradicated place them in the microwave for a couple of minutes.