I love my stick blender but I don't always use it. If the recipe looks like it's tracing quickly I use a spoon or stir with the stick blender turned off. But it really does a nice job evenly blending additives, exfoliants, colorants, etc.
If you use your stick blender, let any soap residue saponify for 24 hours and then clean it, I personally wouldn't have any problem then using it in the kitchen. What you have left on the blender would be soap, right, albeit not completely saponified? But that's just my opinion. Some people are squeamish about lye/food cross over and that's perfectly legit. Also my stick blender is stainless steel and comes apart for cleaning; not sure how I'd feel about plastic.