That seems like a lot of work. Did you use a better quality fluid? Is there a reason you didn't take it to a shop for this?

There is a shop close to me that charges $99 to flush the transmission.

They have a machine that they connect in line with the fluid. They circulate the fluid then pump in new fluid. They use 1.5-2 times the fluid need to fill, this makes sure that it is flushed well.

Only draw back here is you have to use the fluid they use. You couldn't replace with better fluid or synthetic, etc.

I've had them do all of my cars over the years with no issues. Plus they are so much cheaper. The other places I know that do this charge $150+.