Thumb sucker

Lu

Hey y'all my kid while relaxing almost always has this thumb in his mouth. To sooth himself. To fall asleep. When he is bored. Anyone able to get rid of this habbit? Any tricks or tips? I bought some yucking tasting nailpolish but I'm a bit worried about the chemicals in it? Idk let me know if you guys did something similar! Thanks!! 💙💙