Infiltrate the Freemasons? But isn't that exactly what the Satanists did?
You're right, Steve.
Many of the founding fathers, like Washington and John Quincy Adams spoke out against this later in their lives, even though they had originally been Freemasons themelves, alluding to a corrupting influence of "the French lodges".
The mantra of Freemasonry was never really admirable IMHO, but after the infiltration by Weishaupt and the Illuminati it got much worse.
As you say, that may be the inevitable course of infiltration within any group. Positive reformation seems more associated with the creation of a new group, like Luther's rebellion against the Vatican.