Only if you're obsessive compulsive. I clean records that appear or sound dirty. It doesn't always help, but at least I give it a try. With brand new records, I don't usually clean them before listening(I know, burn me at the stake). If I don't like them, I'm not going to keep them and it seems a waste to spend time cleaning them until I'm sure. By the way, I use a Nitty Gritty 1.5FI and it takes me a minute and a half max to clean both sides of an LP.
Is it necessary to clean every record?
I'm constantly buying used records, some of which are in excellent to mint condition. I put them in an ever growing stack of "to be cleaned" records, some of which are now several years old, because I have a rule not to play records that haven't been through the VPI machine. Is it really necessary to clean the ones that appear as if they've never been played? I listen to a Planar 25, Classe integrated, and Spica TC-60's. I'd appreciate your thoughts.