Is there a (currently working) way to access DOM/JS from an applet in FF?

(Sorry about the cross posting, but this might be a more appropriate
forum
 than MozDev/apps)

Hi!

As the subject implies, I'm looking for a mechanism/technique (or set
of techniques) to a)manipulate the DOM of a page containing an applet
from the applet itself; and/or b)get a javascript app and an applet
talk to each other, back and forth, pretty much as LiveConnect was
supposed to work.  The problem is that NONE of the code I could dig
through Google (either in oracle/sun or in mozilla.org) works on FF
3.6 / Java 1.6_18 on Windows (or FF 3.6 / Java 1.6_06 on Mac OS X).
E.g., JSObject returns a "window" object that then won't return its
document (but null instead), and if I eval "alert('Hello world!')" on
said window (in Java) FF will indeed display the alert dialog (just
like from JS, yaay!) and then immediately and irreversibly freeze
(bummer).  DOMService (again in Java) doesn't work much better since
any attempt to get the document from a DOMAccessor is rewarded with a
DOMUnsupportedException (supposedly caused by an
AccessControlException, but apparently even that is not reliable ...)
Of course, it doesn't help that the code samples I've found range
anywhere from 1 to 8 years back ...

So ... Is there a reliable way to achieve what I want?  An
authoritative, *up-to-date* resource I'm overlooking?  Should I direct
this enquiry to a specific team/person in MozDev/FF?  Thanks in
advance for any help on the matter!