Bad Breath/Post Nasal Drip

I suffer from pretty bad breath which i'm sure is releated to sinus, it's been blocked for some time and i would appreciate any advice on productsi can use to shift whatever is in there.

A few years ago after a pretty bad dose of flu i tried clearing my nose by doing that thing people hate by snorting air back threw my throat and out popped two very large almost ping pong sized lumps of mucas, surfice to say the experience was unpleasent and i nearly choked to death on one of them but my sinus for the next few days was so clear and comfortable until it bunged up again, I'd like a more permanent treatment for this like a nasal spray or something, prefferably oen that doesn't sting or irritate my nose/throat.

EDIT: I would preffer a prduct that i can get in the UK

Tristan. I find a lot of this problem is down to diet, too much fatty stuff, cheese, dairy foods, full fat/semi skimmed etc. Drink plenty of water too, this helps thinout the mucus. It's not very pleasant, especially first thing in the morning. Try not to rely too much on nasal sprays. I find fizzy drinks like Cola etc, promote thick mucus, as it contains a syrup.

I do drink alot of tea thoughout the day with semi skimmed milk, as far as other dairy products go i don't have much. My diet is fairly balanced compared to most people, I don't drink fizzy drinks.

I don't want a daily nasal spray just somethingi can use occasionally.