In short, the easiest way I see is to override a function:
(eval-after-load "flyspell"
'(defun flyspell-mode (&optional arg)))
, -1 (. C-h f turn-off-flyspell), .
, , M-x debug-on-entry flyspell-mode, (q ; C-h m, ; M-: (info "(elisp)debugger") ). M-x cancel-debug-on-entry, .