Wouldn't they need to at least slow it down to allow the clones to be used in warfare for a number of years?
That assumes that such a thing is even possible. It also assumes that even if it were possible, if it was feasible. If 8 out 10 clones die due to the process is it worth doing? Also even with order 66 implanted in them, they were still part of the Republic Army and may not be seen as being trustworthy in the Empire.
Trustworthiness? They were insanely loyal!
Now, as for its independent contractors:
Yeah... um.... not so much.