I have used it as a curse rather than love spell. It really just boils down to tweaking the prayer.
My advise is put up some protection wards for yourself as this spell has a tendency to be very indiscriminant in its effects. Like taking an grenade to kill a fly. You might get hit by some shrapnel :-).
In my experience, the target went nuts, lost his company, lost his wife and family. He did have it coming tho and he honestly deserved even worse.
I think at most repetition of the orations would suffice. I believe it was 7 days. You could also try augmenting the spell by invoking St. Expedite to "expedite" the working as he works for poundcake. Just make sure your intended target is clearly specified in the working. perhaps a taglock type of item such as hair, blood etc of the target can be used as well to help cement the target into your working.
St Expedite in my experience seems fairly indiscriminant on the type of working asked of him.
I've never tried it myself, but I've done cleanup work for a few folks who tried it and got themselves in trouble. To be honest I think it's utterly stupid to use as a love spell. It's like doing open heart surgery with a sledgehammer. I hate that it's marketed as a love spell with cute pink candles when what you are really doing is binding any nameless dead who happen to be in the area to torment and harass your target. Most spirits willing to do this work are desperate and angry, and are perfectly willing to devour you as well as your target if you're not skilled enough to control them or if something goes wrong. I wouldn't use this for anything except heavy duty cursing and even for that there are safer spells.