Trying to get an idea of how to completely clean these reservoirs

I have been on a mission to clean everything I have to then begin to start a number of new builds. I have enjoyed coolant with colors, but this is beginning to irritate me. I have soaked these in hot water and dish soap. I will try Dawn today and I will also try Barbasol red shaving cream, as I understand it is exceptional at devouring tar from smoke, so what not try it here. I have research the best way to clean plexiglass, as there is nothing I found on how to remove stains like these. I have use a toothbrush and tooth paste, also which is how I got the areas where the pumps where clean. Not sure if I can use use Dawn with bleach alternative, but I will by regular and this today for a try this evening. These spots are extremely hard to get to.

If anyone has a suggestion it would be welcomes, as I have used my experience and knowledge to get this point and I am unsure where to go now.

Thanks in advance for the suggestions and assistance.

[Here are the pictures of my reseviors](https://imgur.com/a/U78Bww9)