If all else fails then use Blackstone Senior's great idea:
When something had to be done without the audience seeing it happen, he had a beautiful girl walk on from the opposite side of the stage to where the prop was--dressed in a short costume & wearing black fishnet tightsl--Sometimes she would drop a tray--ALL EYES in the auditorium when straight to her and the tricky move was done. It may have been the duck vanish when several ducks had to be almost pushed from a sort of cage/box into a hidden area,
SOUND is a great misdirector.
Something my son was talking about on his video call from Portugal last night.
The girl in tights helped too!!!
Fu Manchu (Okito's son not the Sax Rhomer character) did a similar thing. He had to misdirect the audience from a prop on the stage.
Suddenly the comedian in the show appeared in a theatre box--had a row with a girl (a stuffed life size doll) threw 'her' out of the box -- the audience then laughed, looked back to Fu Manchu--and the deed was already done
Allen Tipton
PS If you use the doll--do not buy one from Del Boy!!!

Began magic at 9 in 1942. Joined Staffs M.S at 13. Nottm.Guild of M. (8 times President. Prog Director 20years)IBM. Awarded Magician of Month 1980 By Intern. Pres. IBM for reproducing Dante's Sim Sala Bim. Writes Dear Magician column for Abra. Mag.