Try this:
(defun c:EraseAndDisconnect ( / allReactors obj)
(vl-load-com)
(setq allReactors (apply 'append (mapcar 'cdr (vlr-reactors))))
(mapcar 'vlr-remove allReactors) ; temporarily disable all reactors
(setq obj (vlax-ename->vla-object (car (entsel))))
(vla-delete obj)
(mapcar 'vlr-add allReactors)
; (mapcar
; '(lambda (a)
; (vlr-owner-remove a obj)
; )
; (cdar (vlr-reactors :vlr-object-reactor))
; )
(princ)
)
<edit: code that doesn't work properly has been commented out...>