Collide doesn't work

The difference between what you are trying to do and what is in the video is the video has separate objects that are dynamic - balls, blocks, etc. They are not joined together. There are no examples of having an arm that is part of a somewhat complex puppet that should be restricted by a collision. This is because CH seems to have an internal restriction that one thing can control the position of something. So either the hand will be attached to the arm (which is attached to the body), or the hand can be "dynamic" (free moving) and then physics kick in with collisions etc. You can have things bounce off the arm (by tagging it with collide) - like in the video I did above. You cannot have the arm movement be restricted by a collide layer. If the hand is attached to a body, the body will control the position and the physics is just ignored.

That is my understanding of how it works anyway.

If you do managed to get it to work however I would love to hear how you managed to do it!! The "one parent controlling position" restriction is annoying. E.g. you cannot attach a rope between a dog and a dog walker. There was another similar thread talking about how to do a bicycle here: Bicycle animation .  Again, logic what is wanted, but CH does not support everything desirable yet.

So I could be wrong, but I suspect what you want to do is very logical and not supported. Draggers (I assume you would use a dragger to control the hand position, to move into the pocket?) do not obey collide tags. It just gets ignored.