When I did my motorcycle carbs, I bought a cheap handheld and used baking soda. It did a great job, and any residual soda in the channels will dissolve.
If the carbs are really bad, you will still need to use carb cleaner or whatever to get into the channels and jets...
Tool:
https://flic.kr/p/to1fhpBefore and after of the bowls:
https://flic.kr/p/t6qy2GBody after shot:
https://flic.kr/p/tkEA1L
