DOORS MADE FROM HARD WOODS such as oak are perfect for Soda Blasting. Carved and sculptured designs are easily stripped. These are most difficult with chemical strippers
DOORS MADE FROM SOFT WOODS such as pine and fir are sometimes problematic. The paint is harder than the wood. Removing it is not unlike removing the candy shell from an M&M without damaging the chocolate underneath. There are different types of pine and fur. What can happen on the softer ones, is that the pith or soft part of the wood erodes. The grain in the wood is a sap or resin and is not affected by the soda. This leaves the surface looking similar to sand dunes. It could be also a novel way to obtain a "stressed look". Usually on the soft woods, the edges that were squared become rounded. I had one painter use spackle to level it back out then repainted it.
Metal doors are pretty straight forward. Rust will be removed to a point that it can be repainted with a primer.
Glass and hardware do not have to be removed. Soda Blasting will not harm or degrade them
The number of coats of paint increases the time and cost about 20% per layer.