Yes, I agree. This 'HACK' is something a stay at home parent who has too much time on their hands but swears "OMG IM SO BUSY ALL DAY" (even though their kids are old enough dress themselves and don't get home from school until almost 4pm) would come up with.
I have kids (only one that's pbj age), but it takes me like 30-40 seconds to make 3 pbj sandwiches from start to finish. I really can't see how this would help in any way.
"OMG I HAVE SO MANY ERRANDS TO RUN...OMG"...I hate these people at the bus stop. I do more before and after I go to work than they do all day...these are the "OMG I MADE FROZEN SLABS OF PB AND NOW I TOTALLY HAVE TIME TO GO TO THE GYM" people...I lift at 9pm after I spend all night with my kids...get bent.
Sorry, I feel better now. :)