What is the magic behind Vicks vapor rub?

This is the first time I've got one on the groin. It was hard to concentrate in class. Sitting was difficult and I couldn't sleep properly. I used boil ease and all it did was help with the pain. I put on vaporub last night and the next morning my boil drained. The bump is still hard but I can finally sit and move my legs comfortably. Any tips to help drain out the rest?