I use Dawn Power Dissolver too, except I just use old used toothbrushes with nylon bristles. I don't get too carried away because I'm gonna get it all slimed up again anyway..
I got my bottle at Walmart as well, but I don't recall if it were a "Super" Walmart (grocery) or not. I haven't met an engine that needed anything harsher than that. Some of my engines with barstock heads have gotten some slight surface corrosion from sitting, the DPD does not remove this. I've had to polish that stuff off with a buffing wheel and compound. Any other gunk comes off easily.