Unfortunately this question gets asked a lot here... as you've witnessed, a little clean up at the appropriate time eliminates a whole lot of work later. Having said that, try mixing a 50/50 solution of fairly warm water and common white vinegar. Using one of the abrasive backed sponges usually used for dishwashing, soak the areas to be cleaned with the mixture and let set for a few minutes. Using the abrasive sponge keep the area wet as you clean. This usually works quite well. There are commercial solutions can buy at your DIY store, but since I'm in the U.S., the brand names may be different... Best of luck!