Loic, you can't bust through a line of untouched 3 x 6 setups; they are very tough. However, notice that Scorpion's chain from G14 to Q10 is pointed in the wrong direction at each end - towards the black walls. He needs to turn towards white, and while 8. l16 was a try in the right direction, it did not block the G14 peg in any way, allowing Scorpion to obtain a bigger advantage.
That said, you might have tried 8. h18 and if, say 9. j17 then 10. k15 11. i15 12. j13 busts his continuity and turns the advantage back to you. The idea is that by making effective blocking threats below his chain, it gives you a chance to make a DOUBLE THREAT (k15) and interfere with the 'untouchable' chain.
At least that's my 1700 opinion; I'm waiting for it to be proved totally wrong, now!! (meow)

WOW!! NOTHING WAS HAPPENING WHEN I PRESSED THE COMMENT BUTTON, SO I PRESSED IT A FEW TIMES. NOW MY COMMENT PRINTED 3 TIMES. I HAVE NO IDEA HOW TO REMOVE THE EXTRAS! SORRY ABOUT THAT! (MEOW!!)

(getting used to using Commentator; not here too much; I thought my comment repeated, but NOW I see that it did not!!?? oh, well ... sorry for the inconvenience, and my no-doubt incorrect analysis)
> . . <

I think |8.h18 could be countered with a white peg that uses both L12 and G14 to get to the bottom. For example 9.j16 or even 9.l16.

So, I post my original idea here, |8.j7 (threatening Q6) and after 9.p8:
10.h17 11.h16 12.i15 13.g18 14.h13 15.h12 16.i11
10.h17 11.h16 12.i15 13.i14 14.j13 15.j12 16.g19 17.k14 18.m17
10.h17 11.m14 12.m17

Seems like it doesn't work because white can play |8.j7 9.p8 10.h17 11.l16 anyway.
Maybe all moves left to the K-rank are already losing due to this threat.
|8.k16 9.i15 looks good for white.
Who finds something against |8.k17 ?