The two indirect methods that Gu Hang thought of have both been used.
First employed, were the Priests.
How to communicate with a deity? The most straightforward method is, of course, through his clergy, which are his priests.
According to the National Church doctrine, every citizen of the Empire should devoutly believe in the Emperor. In this way, every thought and prayer of the people can be heard by the Divine Emperor. With enough sincerity, they may even receive a response.
Of course, whether this is really the case is another matter.
But the point Gu Hang can be sure of is that sincere prayers of believers can truly be heard by the deities.
Gu Hang has experienced it himself in the Storm God Kingdom.
And while the priests may not all be extremely devout, statistically speaking, they are indeed more devout. Moreover, some of the prayer rituals they perform can enhance the connection with the deities.