Video said that the shortest solution required at least 22 moves.
I'll drop the sequence below unless there's a rule not being mentioned by the video.
SPOILER BELOW:
Starting with white assuming a1 is bottom left corner
1.Nc2
2.Ka1
3.Rb2
4.Ka2
5.Nca1
6.Kc2
7.Rb1
8.Nb2
9.Kd3
10.Kd2
11.Kc2
12.Nd3
13.Kb2
