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,

Felisia