With a little bit of persistence it is possible to create better looking models with 123D Sculpt+.
You can make basic colour/diffuse, roughness/glossiness and bump maps within 123D Sculpt+. The thing to remember is that you need to have the exact UV texture map for every texture produced. By duplicating your original model to create a new texture effect you are keeping the same UV texture coordinates that is needed for the final model.
Duplicating the model is like having texture layers in a paint program. When finished you can export the models and extract the texture within the zip file to get a new effect texture that you can edit in a paint program to improve or upload to Sketchfab.