No. There is no evidence to suggest that subliminal anything convinces people to buy something. Besides, how would you measure something like that? Do you ask people if your subliminal advertising worked? It sounds like one of those "it can't be provable or unprovable" things ad agencies like to talk up because you're never quite sure if it works. If you can't track the results of your advertising you just threw money away into a black hole.
Subliminal advertising does nothing to counteract "buyers remorse" which is what any ad writer has to get around that. Such ads use facts and figures to convince people they already made the right decision. Subliminal advertising doesn't allow for that, therefore it's ineffective.