I have a $900 american-made carb-specific ultrasonic cleaner (a $79 Harbor Freight cleaner is nothing more than a low-end jewelry cleaner- a complete waste of money for carb work) that I use to clean carbs for a local mc shop that sublets their carb work out to me and I've seen countless idling issues resolved with a true carb cleaning using the appropriate chemicals and no, Simple Green isn't the answer unless the carbs are not truly that bad to begin with.
I use a Simple Green-like product as a pre-wash but the real cleaning is accomplished using a shellac-dissolving chemical designed specifically for carburetors; I source this from a chemical company in Wisconsin and it costs me $75 per gallon but works great and is worth every penny. It is environmentally-friendly, non-toxic, and non-flammable (important because the ultrasonic cleaner uses high heat in conjunction with the ultrasonic wave cleaning) and reusable; these unique attributes contribute to the steep price of the product.
The dealership has seen the results of using this process and the appropriate chemicals time and time again and that's why they continue to send me their carbs; my cleaner has solved countless idling issues because you simply can't access all of the passageways by hand and you can't confirm visually that they are all completely clean.
Without this step, you can never be truly sure whether any lingering carb issues are mechanical in nature or are simply clogged idle/slow speed circuits; nothing cleans those tiny passageways like a true ultrasonic cleansing. Does every dirty carb need this procedure? No, if the carbs aren't truly that clogged, perhaps a simple cleaner will do the minimal job needed but I've seen firsthand countless examples of people "cleaning" the carbs themselves and then bringing the bike to the shop because it still didn't idle properly; The shop calls me, I disassemble and clean the carbs properly and the problem is usually solved. Obviously, if there are mechanical issues with the carbs above and beyond being dirty/clogged, no type of cleaning alone will cure all of the problems.