Golf IV Heated seats DIY

Hello! 

Think I've got myself some golf MK4 heated leather seats I'm going to fit to my Octavia boggo spec.

I've seen people buying looms from kupetc or somewhere... Not too interested in that. 

Also don't fancy spending £20+ on some second hand switches which may or may not work.

I was thinking of using a potentiometer fed by inline fused ignition live. Then from there to the seat. 

I think I can get my head around the wiring using this handy diagram I found.

But I'm wondering if a potentiometer will work as the switch, and if so, what size will I need? 

The potentiometers I've played with before click off when turned right down which is ideal.