Using phys_timescale?

I have seen a guy on YouTube use the console command phys_timescale and a NPC ragdoll were flying slow. My NPC ragdoll is not able to do the same? How do I do the same?

you have to put a number in front of phys_timescale that coordinates with the actual speed you want it to go, for example, phys_timescale 20 . try experimenting with the numbers to see what is the best speed for you. although, i do remember seeing an option in the Q menu with the timescale so you can edit it there.

sv_cheats has to be set to 1.
phys_timescale 1 is the default speed.
phys_timescale 0.2 is slow motion.
phys_timescale 2 is super speed.
Note that **phys_**timescale will only make props move slower, not players. If you want everything to move slower, use **host_**timescale instead.