The kind of poo thats stubborn haha.
Try dipping in warm water then with a warm damp cloth just rub a little obviously gently and it should come off eventually. If its in the nails use a toothbrush to get it out.
Also if the damp cloth doesnt work, try brushing it off with a wet toothbrush.
Another way is distract with favourite food and then with the damp cloth rub gently and it shuld come off.
Holly gets this a fair bit (no idea how) so I learnt the ways to get it off. Though shes more difficult because she hates baths so I have to do it without being able to dip it into warm water. Which sure makes it easier.
Good luck !!