The problem is...Why are you doing it????????

As we have already discussed, last night , dog poo is not a disgusting mess to another dog. By forcing her face near the mess all you are doing is showing her where she made a mess. This is pointless because she already knows that! You are telling her off at the same time so the only connection the dog can possibly make is that you get excited when she sniffs at her own mess. You are correcting (a very loose definition of the term) her looking at the mess, not doing the mess.

If you catch her DOING the mess - she will connect your reaction to her action.
By pushing her nose into liquid or solid mess (I know you didn't actually do this) you also risk the dog inhaling matter that could do damage to their respitory system. Especially in puppies that have not been through a full worming course you are also going to reinfect them with any parasite they are carrying.

From a training point of view you are also making your hand on the top of her head a threatening object.

It is a pointless excersise and it was not this that house trained your dog - it was the other things that you did, I promise you.