Betta and snails in a one gallon tank?

I have been doing my research and I have a crowntail betta fish in a 1 gallon tank. I love my fish very much and I'm trying to add things that will make him happy and his enviornment the best it can be. I have read that snails are good to put into tanks with bettas. If I put in a snail does the water have to start being filtered? I do not filter my water now, but I do keep it clean. Are there any specific types of snails anyone could recomend? And while I'm at it, could I put brine shrinp eggs in also? Bettas like live things to eat and I am also purchasing bloodworms. Thanks! :)