Like Robert said NO TOOTHBRUSH!!!
I too use dawn soap and water in a plastic baggie in a hot ultrasonic for 3 or 4 minutes then rinse and repeat, rinse and repeat again if necessary
Depending on what it is and how much resin has clinged to the model will determine how many times you clean it.
One other thing do you notice a difference between cleaning the resin model within the hour of print finishing on the printer compared to a print that has sat in the printer for 5 hours?
I would test that theory. I have left my print hanging overnight, in the printer, before if I start a long print before I leave work but otherwise I don't leave it in for much more than an hour using the same cleaning process I described so I have not experienced this.
Plus I use a B9 curing machine and have never left it in the sun. I just don't know how it can cure better than the UV curing.
I'm so far behind I think I'm First !!