Cleaning aluminum ?

Question:my dog kept eating all the plastic water dishes i brought home for her she even ate a couple of light steel ones.so i went to a yard sale and bought an old aluminum pressure cooker pot. problem solved. except it has this calcified stuff growing inside it and i cannot remove it..
any suggestions?

Answers:
Kleen King is a cleanser made specifically to clean alumium without pitting or turning it black like most cleaners will. It is inexpensive and you can find it at the grocery and discount stores near all of the dish soaps. Just rinse it out of the pot well so your doggies water is safe.