yeah I used that technique a bit also...once he came out halfway to find out where the mouse smell was coming from he decided to start going back in. At that point I grasped him firmly so he couldn't retreat and spent about a half hour doing the pull-wait-pull routine to get his rear half out. It was pretty fun...a test of wills kind of
he held on with every last centemeter of his tail...little stinker

if I thought he was in danger I would have taken the chair apart....a wrecked chair is a small price to pay to get a snake out of a bad situation. Luckily for the chair the space he was in was a snug little pocket with no sharp metal bits or other dangers.

from now on we're going to do all our roaming and sitting on the bean-bag chair...no spaces there!

meanwhile, he has spent the day trying to convince me that if I gave him a SECOND consecutive meal it will help him get too big to fit in the chair.