No, since the greeting is being made to him or referencing him as the leader
- he would not greet or reference himself
By autumn 1923, some members of the Nazi Party were using the rigid, outstretched right arm salute to greet Hitler, who responded by raising his own right hand crooked back at the elbow, palm opened upwards, in a gesture of acceptance.
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The form "Heil, mein Führer!" was for direct address to Hitler.
The German version of the Wikipedia also states:
Hitler hatte den Gruß aber auch aus seiner österreichischen Heimat mitgebracht, wo „Heil“ als Gruß unter Freunden verwendet wurde – und in den westlichen Landesteilen noch heute verwendet wird...
Hitler had also brought the greeting from his Austrian homeland, where "Heil" was used as a greeting among friends - and is still used today in the western parts of the country...
So if Hitler did ever reply, the single word Heil would have been used.