Good afternoon;
Hoping someone has given this a try on their 3 head Specific keg washer.

Want to switch to acid cycles on our Specific SMS 913-A Keg washer.
Will be using mixed cultures, and would like to prevent cross contamination of brands.
Cannot just keep "mixed culture kegs"; wish I could, but don't have the space to store them and it doesn't make sense to store empty kegs when I could use them for something else.

Current Set up:
I have a Beta pump unit that has two dosing pumps on it.
One doses caustic into our cleaning reservoir.
The other dose pump doses sanitizer to our kegs during a sanitizing cycle.

We have a conductivity sensor in the cleaning reservoir that measures free ions...not sure if they measure hydroxide or hydrogen.
I have been in contact with Specific, and I have not gotten a definite answer from them. They have said different suppliers of acid detergents may have different concentrations, so the conductivity probe may instruct the dosing pump to run...or not.
I use AC-Special from Ecolab for acid washing my fermenters, which is an phosphoric/nitric acid blend...pretty light on the nitric.
Would like to use this for my kegs as well.

Specific has suggested I just shut off the power to the Beta dosing pump to the chemical reservoir side...
This would then prevent any sanitizing cycle on the kegs, which I feel offers an additional step towards good a cleaned and sanitized keg.

Has anyone cleaning kegs with acid on a Specific SMS 913-A 3 head keg washer?
How strong of a concentration of acid have you used? I was thinking of 2% and above.
Did varying strengths of the acid affect the conductivity probe to turn on/off the respective Beta dosing pump?

Any help is appreciated.