If it's just your Sapphire game, you should try q-tips + rubbing alcohol. Be careful if you choose to do this.
Blowing into games can corrode the contacts over time and isn't recommended. If anyone has gotten their NES working after a long period of time, some games will have more trouble working than others because they were blown on too much.
Q-tips and rubbing alcohol render my games unplayable for about a day whenever I use it. The game either won't work or it'll freeze about 2 minutes in and it won't work properly until like the next day. I wouldn't recommend it. Although it does get rid of any dirt or whatever else might've gotten into the cartridge.