The 21-year-old created brand Dench with rapper cousin Lethal Bizzle, and Frimpong has said that the pair are now trying to think of names for a new line.
"Me and Bizzle just sit around the house making up words," The Sun quotes Frimpong as saying. "We were playing FIFA, he scored a goal and we started saying Dench to celebrate.
"We were hungry for some money, so we made up the T-shirts and they've sold really well. I couldn't tell you our new words, if I did nobody would buy the shirts. It's got to be a surprise. Maybe Kling-Kling, you know what I Ming-Ming?"
The midfielder has failed to cement a regular place in Arsenal's starting XI due to a host of injuries.