Sableye is the only Pokemon who gets Stall so hypothetically the practical uses;
Nothing.
SubPunch would still not be a good idea, due to Sableye's low attack and without the usual proper investment, it's defences fall and it can get beaten down really fast especially since it has to take an attack and also have at least 25% to get a sub up.
>About the only thing it does for Sableye is ensure a full-powered Payback, which isn't really worth going last every turn.