When you lie on the bench, make sure your butt, upper back and head are all in good contact with the pad, and keep it that way all throughout the movement. (fitnessandpower.com)
If you have access to a T - bar bench, your chest will make contact with the pads of the station. (ironmanmagazine.com)
This should be in contact with the pads about 10 - 15 minutes a day (chlorhexidine works by contact time). (animalwised.com)