One squirt a day I reckon... Not sure one a month would be terribly effective...
I was a long-term user for a chronic sinus issue, but these days I find I manage well if I use the spray only when I have flare-ups, and simply use half a tab of cetirizine to keep the hayfever under control. I don't really remember having nose bleeds, but sometimes the stuff didn't half sting...
My hayfever/allergic rhinitis/whatever it is is
very mild nowadays and has been getting milder as I get older. It was horrendous when I was a teenager; back then there was only the 'sleepy' antihistamine available which meant either be so sleepy or have a nose running like a tap and sneezing sessions fit to burst and very disruptive for self and others ... I suspect nowadays you'd get special allowances for at least some part of the GCSE and A-level exams, but we just had to battle on ... one girl who was even more badly affected than any of the rest of us, with asthma all through summer, got special dispensation to do hers at the time usually permitted only for re-sits, ie in November, but that was considered very drastic and exceptional.
The past few years I've found that a week's course of almost any antihistamine at the start of the season (need to catch it before the allergic reaction gets a chance to ramp up, as it were) will give me good control for an extended period (maybe just taking a tablet occasionally when the pollen count's extra high) and then another week of tablets after a couple of months and repeat once again to see me through the summer ie February - April - June or thereabouts.
It seems this spray will be even better at a rate of a sniff a month or so; I have to say that I prefer it to the tablet-taking. I used it twice early in February and I've not had the tell-tale allergic 'tickles' until today, slightly. I'll see how it goes the next couple of days but one sniff every six weeks or so is OK by me!