Removing intake manifold without getting coolant in engine

Suction gun? Dont think it can be avoided. Drain oil into a clean pan,re-use it.
I understand your position, but why bother?i would drain coolant, pull heater hoses and blow compressed air out of intake. It likely will leave some behind.
Hope for the best, prepare for the worst.
If a customer told me to save the oil, its not gonna happen. Fresh oil goes back in.