@ crystalrae i believe it would be every day until they break up. vinegar is typically used to destroy or neutralize energy. and i see no point in pouring it on the lemon after the spell has worked.
@ Summer, it's ok, but without all the information we can't help you. i don't know the spell except the one provided, it seems like an alright one, so i don't know too much about the freezer, unless it's suppose to represent 'feelings on ice' or something. you wish to break up the two people, while casting on one person can cause a break up, making both hate each other will make it go faster and prevent one from pinning over the other. of course spells do wear off, and if you do cast this spell, they should never find out as many who do find out these types of spells are cast upon them will turn love to hatred. [just how many love spells work that i've seen]