Deleting ghost layer

 Hi,

I'm trying to delete ghost layers that exists in database but you can't select or view. I can get layers through

foreach(lpp cv~>lpps when(lpp~>purpose=="hv" printf("layer found %s %s\n" lpp~>layerName lpp~>purpose) ) )

dbDeleteObject complains it's invalid type, if I try to use ddDeleteObj then I get

 *Error* ddDeleteObj: argument #1 should be a ddUserType (type template = "b") - db:248248124

What other command can I use?