Dipping is a personal decision that collectors have to make for themselves. Most of those solutions on the market like Tarnex are temporary. Have you ever seen silverware that is dipped into these solutions? It does not last for a very long time before it needs to be dipped again ... and again... and again. And each time it is dipped, the chemical reaction disolves more surface of the object being cleaned. The more the piece is cleaned the harsher the artificial lustre to the point that no lustre remains at all. Most experienced collectors can tell if a piece has been cleaned. In fact, some of the grading services in the coin industry won't even grade a coin that has been cleaned... or if they do grade the piece ... they will note "cleaned".