For christ's sake PAZ turn your capslock OFF!! Nobody likes a shouter

I think we're all getting mixed up with 2 things here:
1: flushing chemical out of the pump & plumbing of the machine, and
2) de-scaling
In a portable, you shouldn't really have a need to de-scale... the majority of the internals are not metal surfaces that collect scale. However once in a blue moon it might do a little bit of good, but not that you'd notice. The only thing you need to de-scale normally is an in-tank heater element.
Phos made by Clover Products is a fantastic de-scaler, and very economical. Basically anything containing phosphoric acid will do the trick, DO NOT use hydrochloric as it will properly screw things up.
To flush out chemical after cleaning, leave the hoses and wand attached, just suck out all the remaining solution in the tank, add some cold fresh water and jet it through. Sorry, I meant dihydrogen monoxide, let's keep it simple!
