On their website they describe how and when to use snotty grotty;
If your baby has the sniffles & sneezes grab your snotty grotty room spray, stop praying and start spraying. Relief has arrived. Snotty grotty room spray helps to clear your baby’s nasal passage, ensuring that they can get a good night’s sleep, without nasty sniffles or sneezes.Earlier in the new year our little man had a case of the sniffles so I started using snotty grotty. I believe it helped him settle to sleep when he was congested with the sniffles. I have been using it ever since as I love the smell of it and when he has the sniffles again it will help clear his nose and thus help him sleep better whilst he gets rid of the cold.