How to clean tubeless tire sealant from rims
I did this weekend it was not hard to do it mechanically with a piece of cloth and water. Then for patching I needed a piece of a very clean surface so I used a dish-washing liquid and then finally isopropanol buth that will probably not be necessary if you do not need patching.

From the rims the mechanical way was enough, a dry piece of cloth or even just fingers were fine, but a wet cloth will be easier.