the swirls come due to the washing process. especially if using a sponge as it traps grit between the sponge and paint and you then mark the paint. srp and black hole are awful for the amount of baulking chalk.they do this to help hide swirls but once washed its back.
thats why you should do a proper job(even if you do stages over a week) and compound the car to remove the swirls. the protect it and use the correct process to wash and they shouldnt come back.