Source old google ads account from my legit MCC for blackhat purpose - How to do it?

Hey guys!

I have a 7 yrs + mcc I use for my agency and there are some old unused accounts in there I would like to use for cloaking and black hat stuff.

Is there a way I can switch them to another MCC without having problem with my legit MCC?

I have to use proxies? How would it work?

Thanks!