I worked with this on the computer, decided since the video shows notation that I'd use some, and somehow went wrong. Hence with a printed version and pencil I tried again, and got it notation free, not timed but around 1/4 hour. I did mark positions for 6/9 and 3/5 pairs, and later the most helpful 6/8/9 triple in box 6. I marked later on another strategic 2 & 3 in R4. By 'marking, I mean just circling or ticking the cells involved, no numbers., they were in my head.)
At the 16:00 mark, if you look closely, you can see both the 3s and 5s are excluded from Col 9 in Block 6, thus R6C9 can only be the 4. This allows you to progress easily quite a bit further. Eventually, it is a 3,5 pair in Col 5 at Rows 6 and 9 that allows you to finish without notations.
I worked with this on the computer, decided since the video shows notation that I'd use some, and somehow went wrong. Hence with a printed version and pencil I tried again, and got it notation free, not timed but around 1/4 hour. I did mark positions for 6/9 and 3/5 pairs, and later the most helpful 6/8/9 triple in box 6. I marked later on another strategic 2 & 3 in R4. By 'marking, I mean just circling or ticking the cells involved, no numbers., they were in my head.)
At the 16:00 mark, if you look closely, you can see both the 3s and 5s are excluded from Col 9 in Block 6, thus R6C9 can only be the 4. This allows you to progress easily quite a bit further. Eventually, it is a 3,5 pair in Col 5 at Rows 6 and 9 that allows you to finish without notations.
I rather saw the 689 triple in block 6. Against all odds :) :), it leads to the same result. Nice catch.
I started this at 15.43 in the video. 7 minutes, notation free.