I was lucky enough to have a friend who spent an entire day fishing several years ago to get one and he traded an egg to me in exchange for my Metagross so I didn't have to do it myself. As a result I always make sure that I have an egg/ Feebas/ Milotic on at least one of my 3rd gen games so I don't have experience the pain and torment he had to go through. I've only used a Miloic once during a play through of Sapphire and I found it to be pretty darn effective as it could take a lot of hits and still hit the opponent back pretty hard.