I admittedly don't know how submersible pumps compare to regular pumps, but I have this pump, which alleges to pump 14 GPM, and I also have a Spike Flow, which is rated at 9GPM. I've never done a side-by-side but I find it really hard to believe that submersible pump moves at a higher rate than my Flow.

You may have already seen it but Spike does sell this CIP ball designed for smaller pumps. I've been eyeballing it but have a hard time dropping $65 on it, then having to come up with an adapter to allow my hoses with quick disconnects to attach to the 1.5" TC fitting.