Headhacks using Lua?

Is it possible to make “headhacks” using lua? I have tried using ent:AddEffects(EF_BONEMERGE) and scaling down every bone except the head on the model which has the head I wish to use and then the opposite on my playermodel but once I scale down my playermodels head the merged head also scales dont and I cant scale it up again. Is there any way to get around this?

Parenting the new head to the forward attachment here wont help as the end goal is to make a full clothing system.

EDIT: Fixed it by setting the playermodels bone scale to 0.1 instead of 0 and then making the merged one 10.