I've had very good experiences with both Sonus All-in-1 TAC and Chemical Guys Nonsense; very underrated products. Both far exceed anything else I have used for spot-treating stains, and have performed wonders in situations where my Optimum Power Clean (which I found to be a bit overrated, TBH) or L.A. Totally Awesome :hotrod2: struggled or were completely ineffective.
The Sonus and Nonsense products are more cost-prohibitive when compared to the likes of Meguiar's D101 and some of the less-costly concentrates, though. This is applicable to the Sonus APC, especially, given that I have only seen it retailed in 16 oz. quantities ($9.97 right now through Autogeek).Maybe just keep a bottle on hand exclusively for spot-cleaning? You can pick up a gallon of the Nonsense for around $27 - $30, depending on the retailer. Can't say how expensive shipping to HI would make these products........
Good luck.