Rubber seal cleaning is a Ha-Ra tip that can save you a lot of time and effort.

Put 2-3 drops of Protective Formula on a damp Ha-Ra cloth (e.g. Ultra or Star), foam it up slightly and carefully rub it into the rubber seals of your car doors. This will make the rubber soft and supple again. The Hans Raab Protective Formula for cleaning and care can be used not only for the car, but also for all other rubber coatings in the household e.g. fridge doors

Ha-Ra Australia