How to effectively and efficiently remove varnish from wood
I've had great results using Citristrip, (see below). I've used it indoors many times and it leaves no fumes. I've used it to strip multiple layers of paint and varnish from furniture.



There are many products to choose from but I know this one works. It just goes on with a brush. Good luck, you took on a big job redoing a staircase.

This product looks similar due to the fact that it is for indoors and is a gel, which is what you need for a staircase. Verity it with the store personnel. It is sold in your neck of the woods.