Land and buildings belonging to at least 600 developers, businessmen, and farmers have all been put into this trust since word about it began to spread late last year.
They are hoping the courts and lenders will be unable to get at the assets because of the ancient and complex trust laws.
Once in this specific trust, people have stopped making loan repayments and, where receivers are in place, they have been told to relinquish control.
In recent months demand to get into the trust has swelled, with Mr Cullen among those who have put properties into it.
He has up to €8.5m in debt with ACC bank but his spokesman would neither confirm nor deny his relationship with it.
Mr Cullen is not the only businessman with large loans to link up with the entity.
The trust is run by a Kilkenny-based businessman Charlie Allen Sr, ostensibly as a philanthropic service for those who stand to lose properties to banks or private lenders.
It is designed to operate as a private entity which courts cannot get access to.
Recently the trust has been used in at least two distressed auctions to at least temporarily block intended sales of freehold properties.
The process involved telling the auctioneer, his insurer and, if necessary, the would-be buyer that the property cannot be sold with clean title.
However, it has yet to be tested in the courts to see if the private trust law it is relying on can legitimately thwart the rights of lenders to seek and enforce repossession orders.
Individual lenders have said it will be unravelled but it has yet to be fully challenged.
Knowledge about the existence of the trust has spread by word of mouth and, to join it, people have attended group meetings, mostly in Cork.
Interested parties must prove they own the properties in question and that it has not already been sold.
People have to relinquish their property rights in favour of long-term leases.
To place a property in the trust, people are charged a small administration fee and, once their properties are signed over, they rent them back on long leases for nominal rent.
It is understood borrowers who put commercial properties into the trust have been asked to make a donation proportionate to their borrowings.
Despite its growing popularity, there is no general understanding of how the trust can trump commitments borrowers have made in their loan agreements.
Jerry Beades, chairman of the Irish Friends of Banking group, said he is aware of the trust but remained sceptical about its prospects for success.