Does the President go slithering through Russian “back channels”?

Once more, no, no reference to current events.   Just a bit of history here.

Dark doings in October of 1961, a time of crisis:

Folded inside the day’s New York Times, Bolshakov carried a twenty-six-page letter from Khrushchev to Kennedy -- a personal letter … Khrushchev proposed that the two leaders deal one-on-one,  using private letters to bypass old bureaucracies …
Khrushchev had written that Kennedy could ignore the letter  and that would be the end of it,  no one would ever know it happened.  But Kennedy answered with ten pages of his own ….

-- Richard Reeves, President Kennedy:  Profile of Power (1993), p. 238-9

And, after the crisis had been resolved:

There the negotiating stopped,  but the secret personal correspondence  between the leaders  continued,  often in pretty chummy terms.

-- Richard Reeves, President Kennedy:  Profile of Power (1993), p. 456

(In diplomatic history, “back channels” are a traditional and appropriate way of doing business, as are back rooms.)