Just for curiosity; why such a long time

If it is, as the other posts suggest, high leakage electrolytics, then you want the electrolytics'
electrolyte paste to be completely chilled. Since this is aqueous, dense paste it has a relatively
high heat capacity and at best only moderate heat conductance. 12 hours is usually ong enough to
complete freeze chicken pieces, so it should be more than adequate for electrolytics, none of which
in such a device should be as big as chicken parts. Now if it were old DEC power supplies, for example,
I'd suggest longer, they often had electrolytics as big or bigger than a 40mm round, which would have
longer characteristic cooling times.