I know that you can form a verb from 擬態語 or 擬音語 by adding する after them, but in this sentence it appears the writer used -る instead.
会場に向かう前にもじゃった髪の毛をどうにかしようと行きつけの美容院に行ったんです。
Is it something common? Or just something weird that the writer did here? Thank you for your help!