Clear coolant suggestions for a watercooled PC?

Hello! I've had a watercooled PC for a number of years, but more recently it's been difficult to find EKWB Cryofluid Clear at reasonable prices. I'm thinking of switching to something like Mayhem's x1 coolant, or Alphacool's eiswater.

Any suggestions? Will it matter that some old fluid might still be trapped in a rad even after a flush? I'm hoping to not do a full teardown.

I'm thinking about going with this:

https://www.performance-pcs.com/water-cooling/watercooling-fluids/watercooling-fluids-additives/mayhems-x1-coolant-1-liter-clear-mx1c1l.html