If you want to skip the awful smelling phase, use some citrus for the first few days. Pineapple juice works, recently did one with orange juice. Gets the ph low enough so lactobacillus can thrive. Gave it an extra week to build some strength before baking and yeah, works great.

I just did equal mass of juice and flour, prefer 100% rye or whole wheat to start, 50g each, add more ap flour after it’s established.