I agree with Marda on this. I understand all behavior as a strategy to get some need met. Of course with an inexperienced and powerless child, those strategies can be pretty ineffective and hard for adults to comprehend. It sounds rather like you've got a daughter who is begging for more control in her life, and she's doing what she thinks should work (especially based on getting to change clothes a few times), but now they are not only not working, they're earning her additional layers of punishment and restriction. If I were her, I'd be terribly confused at this point, and probably frustrated and angry.
I'd be tempted to buy four to six nice tee shirts, cute but all identical, and four to six identical pants. She starts the day in this outfit. When she has an accident, she gets the same outfit. But, when she uses the potty, she gets to choose an outfit of her own. So she gets what she wants for staying clean and dry. Everybody wins! If she has another accident, she goes back to the basic outfit again. You probably won't even need to make a chart, because the reward is instantaneous, and if your theory about the "accidents" is correct, she will probably get the point in a few days or less.
Since changing clothes is such a treat for her, how about getting together a box of dress-up clothes, hats, shoes, jewelry… ? Have dress-up parties on some day of the week when you have time to participate and admire her costumes. This might be held as an ultimate reward for getting the potty routine under control again.
I'd also be very consistent in noticing other things that you like and appreciate. Let her know how much you enjoy her "pleases" and "thank yous," notice when she does something you ask without having to repeat, or even more so when she voluntarily cleans her room or carries dishes to the sink, or whatever little tasks she tries to help with. Kids thrive on recognition and appreciation.
There's a marvelous book that describes exactly how to be compassionate and respectful of the child while being clear about your own expectations and need for cooperation and respect. It gives examples for just about any parenting situation you'll find yourself facing. Parenting experts Faber and Mazlish will show you How to Talk So Kids Will Listen, and Listen So Kids Will Talk, in a clear, easy-to-read cartoon format. You'll be glad you tried this approach! My Grandboy 4.5 responds to this approach, and comes up with charming and creative solutions for his own problems.