I am surprised I have to post this, but.... I have seen it too much of late...

If you wish to call a .net method from an orchestration, you could put it in as a variable and then call the method using the variable, this would require the class to be serializable, or use an atomic scope.... bad idea on both fronts....

Make the method a public STATIC method, and simply put the assembly in the GAC. There is no variable, no serialization, required.... just call it using the name space and method name of the class.

EG: MyNamespace.coolclass.methodname(abcd);

You can call methods that are void or that return some data... Try and not return xml document... see my other posts on that...