autoclave qualification

Hi, I want to qualify autoclave. For biological challenge in liquid product, I want to use spore strip as indicator. Because I’ve heard that indicator in ampules type can influence heat penetration as barrier. Could I put the spore strip into the liquid product? If I put it into the empty chamber, could it represent the condition? Because I think air is the worst heat conductor. So if it can be success in the worst condition, it will be applied in common usage, isn’t it? Thank’s before.

Best regards,