Because the Five Viscera Gods are only at an early stage of development, far from perfection, Li Zhirui doesn't even have the ability to mobilize them out of the organs.
It's like a lit candle that could be extinguished by the slightest wind or rain.
The reason the Five Viscera Gods were so quickly refined to perfection in the cultivators Li Zhirui initially experimented on was because he piled up a large amount of Spiritual Objects and nurtured them lavishly. It was like a castle in the air, seemingly splendid but lacking a main supporting pillar inside.
After all, Li Zhirui was only interested in observing the effects at that time, unconcerned about the life and death of those cultivators.
However, when Li Zhirui started cultivating himself, he definitely would not use such risky methods that could leave hidden problems. He was extremely cautious, devoid of any rash or adventurous ideas.