find . -name "*.BAK" -exec rm -rf {} \; -print

man 1 find

       -exec command ;
              Execute  command;  true  if  0 status is returned.  All following
              arguments to find are taken to be arguments to the command  until
              an argument consisting of `;' is encountered.  The string `{}' is
              replaced by the current file name being processed  everywhere  it
              occurs  in  the  arguments  to the command, not just in arguments
              where it is alone, as in some versions of find.   Both  of  these
              constructions  might need to be escaped (with a `\') or quoted to
              protect them from expansion by the shell.  The  command  is  exe-
              cuted in the starting directory.

{}: find로 찾은 path 목록의 개별 원소.
\;: -exec 커맨드의 끝을 나타내는 지점. 쉘의 연속명령에 사용되는 세미콜론(; )으로 해석되지 않도록 백슬래쉬(\)로 escape를 한 것.