Ah, so that's what the hold was for. I found the wall jump tight enough without it.
I went to the 3 pistons blocking the way and wall-jumped between one of them and the wall. After getting on top of the piston I jumped left. It took me between the white and pink gear mechanisms but instead of moving left when I pressed the key, the spider moved towards the camera, and fell off the map.
I submitted with 40 minutes on the clock (sic) and found it stressful enough.