I'm with Mike on this one, Brian. I've found belt dressing --I'm not
familiar with the particular product you've mentioned, so correct me if
I'm off base-- to make a mess on the belts and the pulleys and to remain
there and remain gummy, requiring substantial cleanup and making more
issues at a later date.
I specified "just a little" to help insure the reader understood we were
just looking for a change, not looking to lubricate the belt.