-
Figured out the solution to this is antihistamine tablets for hayfever from behind the counter at the chemist.
Although @Sainsburys_Ed is right you build up a tolerance if you swim regularly, but you loose it almost straight away if you miss a week.
Infact I don't think its really a tolerance as so much your already blocked so you can't blocked any further.
The pills work well, still feel a little funny but being able to breathe is the main thing.
^ permanent wrinkled fingers!
I found i had this problem but as i've picked up my swimming volumes i don't seem to get so much in my sinuses, i have no idea how it gets in there, but sure with swimming so much you'll stop having the problem soon.