wow scary question.first belt your looking at is your drive belt (runs altinater/air conditioning ect...)your timing belt is hidden under the engine covers.you should not spray belt dressing on the belts, ever! in my opinion.commonly it is used to try to take away a squeak or prolong the life of a belt.if belt is broken replace it.if a belt is squeaking or squeeling like hell belt needs replacing and 1 of the pullys are probly not lined up right.my opinion is leave the can of dressing on the shelf.