The concept is to slowly cut down the area the lone king can go until your king has his king trapped on the edge of the board and blocking any move off the edge by itself. At that point, you bring in the rook/queen to attack the entire edge.
With the queen, you also have the option of the "fatal affair" where the queen moves directly next to the enemy king and within your own king's defense range.
There are only 2 potential hazards. The first is allowing the lone king to capture. The second, more subtle, possibility is stalemate, particularly if you trap his king in a corner.
With care though, both can be avoided without much hassle.
This is interesting. It is clear that it is not allowed to ask this question here on a game in process. However, the exact question is answered extensively in thousands of books, websites etc., and there is no rule against that, even for a game in process (as long as no engines or tablebases are used). Does look a bit hypochrytical, no? Like writing a parking fine for a wheel touching the outside of a white line when there was space enough inside.
Assuming the poster had no bad intentions (until proven otherwise), I would say that some of the reactions are more of a problem than the original violation. A simple reference to the ToS would have done.