Rootstocks for Ferocactus

Does anyone have any suggestions for rootstocks suitable for Ferocactus?

I had originally intended to use Trichocereus bridgesii/Echinopsis lageniformis as stocks since they are a reasonable size & can take a fair bit of moisture, but since it would appear that the powers that be are pretty keen to ban Tb's i'm now having to hunt for a possible substitute.

While i'm at it, has anyone tried areole grafting Fero's?

Cereus or myrtillocactus maybe? not sure if these potentially have "illicit substances" in them, but they are both fast growing and similar girth to T.B.

Personally I'd still use Trichocereus... i doubt you would get pulled up even if they do end up becoming illegal.

As for areole grafting, havnt tried it, but Id say it would work